Branden Fitelson on Cognitive "Biases": Sunday, April 17th at 6:00 pm
TBA.

Location: TBD.

Stephen Stich on TBA: Sunday, March 6th at 6:00 pm
TBA.

Location: TBD.

Tim Maudlin on Space-time: Sunday, February 20th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Tim Maudlin from Rutgers coming to speak on space-time. The dinner will take place this Sunday, February 20th, at 6:00 pm in the Butler College Special Dining Room. Professor Maudlin is a distinguished "Professor II" at Rutgers, where he studies the philosophy of physics. Philosophy doyen Brian Leiter has described Maudlin as one "of the best philosophers" of his "generation". In 2008, he won a Guggenheim Fellowship to pursue work on the geometry of space-time Ð the results of which he will discuss at the dinner.

Professor Maudlin will present a new mathematical formulation of space-time. Physical space-time has a geometrical structure. The formal tools that physicists use to describe that structure are provided by mathematics, and the most fundamental such mathematical tool is called topology. This presentation will present a new, alternative mathematical structure, the Theory of Linear Structures, that can be used to describe this level of geometry. Application of this tool to Relativistic space-time reveals that time alone provides the foundation of all physical geometry.

Location: Butler College Special Dining Room.

Daniel Garber on Science and Religion: Sunday, February 13th at 6:00 pm
For our first Sunday dinner of the spring semester, the Princeton Philosophical Society is pleased to have Professor Daniel Garber coming to speak on science and religion. The dinner will take place this Sunday, February 13th, at 6:00 pm in the Rockefeller College Private Dining Room. Professor Garber holds the Stuart professorship in philosophy at Princeton, and is chair of the department. He is considered among the foremost experts in early modern philosophy and science, and has written highly influential volumes on the natural philosophies of Descartes and Leibniz.

Professor Garber will discuss the relationship between science and religion. What is the problem about science and religion? Is there something about religion that puts it in opposition to science? Or is there something about science that puts it in opposition to religion? Is there an essential tension between the two?

Location: Rockefeller College Private Dining Room.

Sarah-Jane Leslie on Generics: Sunday, December 12th at 6:00 pm
For our final Sunday dinner of the semester, the Princeton Philosophical Society is pleased to have Professor Sarah-Jane Leslie coming to speak on generics and generalization.The dinner will take place this Sunday, December 12th, at 6:00 pm in the Rockefeller College Private Dining Room. Professor Leslie holds the Jacob Viner University Preceptorship, awarded to highly promising junior faculty. Her interests lie at the intersection of philosophy of language and psychology, and she is currently writing a book on generics that will be published by Oxford University Press.

Professor Leslie will discuss generics, which are are sentences such as "tigers are striped" and "ravens are black". They are truth-conditionally complex: e.g. "ducks lay eggs" is judged true while "ducks are female" is rejected as false, despite the fact that only female ducks lay eggs. Similarly, "mosquitoes carry malaria" is accepted but "books are paperbacks" is rejected, yet over 80% books are paperbacks, while less than 1% of mosquitoes carry malaria.

Despite their seeming complexity, Professor Leslie will argue that generics give voice to cognitively primitive generalizations, while quantified statements give voice to more cognitively sophisticated and taxing ones. Further, the puzzling truth-conditional behavior of generics can be explained by an empirically plausible characterization of these primitive generalizations.

Location: Rockefeller College Private Dining Room.

Rational Inconsistency: Tuesday, November 30th at 9:00 pm
We say that a set of beliefs are statically inconsistent if they jointly imply a contradiction. Typically, philosophers contend that inconsistent beliefs are irrational Ð the prototypical case of irrationality, even. Yet it is unclear that this is so. Consider, for instance, a point made by David Lewis. Most people in Princeton, if asked, will agree that:

1) Route 1 runs North-South.

2) Nassau Street runs East-West.

3) Route 1 and Nassau Street are parallel.

This set of statements is jointly inconsistent. Yet, when presented with example, no Princetonian runs to the nearest atlas to figure out what as went wrong. Rather, the usual response is to shrug and go on believing each of the three things. And this, Lewis says, is perfectly rational behavior.

Gilbert Harman makes a similar point with regard to science in the 19th century. Namely, two of the best supported and most useful scientific theories of the era were (1) Maxwell's theory of heat and (2) the geological sciences. Yet Maxwell's theory of heat implied that the Earth could not be more than about 20,000 years old, while substantial geological evidence indicated that the Earth was at least millions of years old. Rather than conclude that one of the theories was false, scientists of the era were willing to live with the contradiction Ð the benefits of both theories outweighed rejecting one of them for consistency's sake.

Beliefs might also be dynamically inconsistent when one changes one's belief over time not in response to evidence. So, for instance, if I believe at one moment that it is sunny outside, and then five minutes later that it is not sunny outside, while gaining no new evidence (or re-thinking the problem), then I am being dynamically inconsistent. Despite many attempts to argue that dynamic inconsistency is irrational tout court, that claim seems hard to defend. Indeed, it seems hard to identify any non-practical reason for being dynamically consistent Ð a result that threatens to make dogmatism perfectly rational.

We will discuss whether such inconsistent beliefs are rational, and why it is that they may or may not be so.

Location: Tower Room, 1879 Hall.

Force: Tuesday, November 16th at 9:00 pm
The concept of "force" is central to many political and moral theories Ð which typically take it that people should not be subject to force (at least from fellow citizens). In some cases, such as unprovoked physical violence, the fact that force has been used is evident. Other cases are much more ambiguous. Consider, for example, the following:

1. Mary's boss informs her that unless she sleeps with him, she will be fired.

2. Smith secretly wants to kill Jones. Smith notices that Jones Ð through no act of Smith's Ð unknowingly and accidentally exposes himself to a deadly poison. If Smith calls 911, Jones will be fine; if not, Jones will die. Smith does nothing.

3. Scott sells James a car, intentionally withholding that a leak has dangerously corroded the brake mechanism.

Do these cases involve the use of force? In general, can the concept of force (and violence) be extended to non-physical cases where there is a major asymmetry of information or power between individuals?

We will discuss these cases, as well as the role of force in moral and political theorizing.

Location: Tower Room, 1879 Hall.

Gideon Rosen on The Necessity of Moral Facts: Sunday, November 14th at 6:00 pm
For our first Sunday dinner of the year, the Princeton Philosophical Society is pleased to have Professor Gideon Rosen coming to speak on the necessity of moral truths.The dinner will take place this Sunday, November 14th, at 6:00 pm in the Rockefeller College Private Dining Room. Professor Rosen currently holds the Stuart chair in philosophy, and also serves as Chair of the Council of the Humanities. He was awarded Princeton's highest honor for undergraduate teaching, the PresidentÕs Award for Distinguished Teaching, in 1997. By popular acclaim, this is his third time addressing PPS.

Professor Rosen will present a novel case against the commonly accepted metaethical claim that the basic principles of morality (such as they exist) are necessary truths. Almost everyone seems to think that the normative facts (facts about what we ought to do, should do, facts about good and bad, etc.) supervene on the natural or non-normative facts. That is, everyone seems to think that any world that was just like our world in every natural respect would have to be just like our world in every normative respect.

But given some (controversial) assumptions, we can argue that supervenience is false. As things stand, you should not kill one innocent healthy person in order to save five (by parcelling the one's organs out for transplant). But if act utilitarianism had been true, then this act would have been obligatory Ñ even if the natural facts had been just as they are. Professor Rosen will defend this counterexample to supervenience from some obvious objections, and then (if there is time) sketch an account of why we find supervenience tempting even though it's mistaken.

Location: Rockefeller College Private Dining Room.

Social Facts: Tuesday, October 19th at 9:00 pm
Philosophers and scientists have spilt gallons of ink arguing about what physical objects and so-called "natural" or "scientific" kinds are. Yet a much more vexing and exoteric question has often been overlooked: what is the nature of social kinds and social facts? How can there be an objective world of money, property, marriage, governments, elections, tennis matches, and philosophical societies in a world that consists entirely of physical particles in fields of force? What types of concepts are we using when we talk about these social kinds and make statements about the social world, and on what basis can we evaluate them as being true or false? To what does a social science such as economics refer when it speaks of money, banks, markets, bonds, jobs, or even "the economy" and how can we evaluate its claims?

The classic text on how to reconcile social kinds and facts with contemporary naturalism is John Searle's The Structure of Social Reality. Searle argues for a two-level theory of kinds, in which observer-relative social facts rest upon brute physical facts yet are not reducible to them. Searle believes that social facts are (i) constituted by the "collective intentionality" of a society, and (ii) play a functional role in organizing social affairs and helping us achieve our goals. In this way, he argues that they can ground both common discourse and full-blooded social scientific endeavors.

We shall consider Searle's views and also develop our own in order to answer the questions raised above.

Location: Tower Room, 1879 Hall.

Normative Reasons: Tuesday, April 27th at 9:00 pm
What kinds of reasons do we have to do things? This is a question of central importance in meta-ethics, and philosophers have divided into two camps over the answer. First, there are the internalists, who say that we can only have a reason to do something (to desire something) if we can rationally reach this desire from the beliefs and desires we already have. Second, there are the externalists, who say that we can have a reason to do something (desire something) whether or not we can rationally reach this desire from the beliefs and desires we already have.

Paul Boswell '10, who wrote his senior thesis defending a particular account of internalism that he calls the "rational ends model", will present his account and lead the discussion. He will discuss what a commitment to internalism entails, why we ought to be internalists, and how we can make sense of being practical rational, as well as rationally criticizable.

Location: Tower Room, 1879 Hall.

Victoria McGeer on Self-Knowledge: Sunday, April 25th at 6:00 pm
For our last dinner of the semester, the Princeton Philosophical Society is pleased to have Professor Victoria McGeer coming to speak over dinner on the fallibility of self-knowledge. Professor McGeer, a specialist in philosophy of mind and cognitive science, is currently working on a book about self-knowledge, provisionally titled Self-Knowledge, Self-Made.

Professor McGeer will be discussing the problem of self-knowledge: On the one hand, itÕs generally acknowledged that we know our own minds in a distinctive way, a way that gives up a certain privilege in our knowledge claims - Descartes, in fact, though that we were infallible with respect to such knowledge. On the other hand, most philosophers and psychologists would now agree that, however distinctive such knowledge may be, it is by no means infallible. This raises two distinct puzzles: (1) what counts as legitimate evidence for fallibility - i.e. how can we tell when people make mistakes about their own minds? and (2) how do we explain the distinctive character of self-knowledge in a way that allows for (some) fallibility?

This is a big topic, but here's an interesting way into it: to focus on the problem of subjective report, and in particular, first-person reports of abnormal sensory and/or perceptual experiences. This topic raises interesting questions at two distinct levels: First, there are philosophical questions about the nature of subjective experience, subjective awareness of experience, and subjectsÕ capacity to articulate what they are experiencing. Secondly, there are questions about how philosophical theories of such matters interact with empirical theories of - and research into - abnormal neurocognitive conditions. To focus her discussion of these questions, Professor McGeer will be considering, in particular, the phenomenon of subjective report in high-functioning individuals with autism.

Location: Rockefeller College Private Dining Room.

Delia Graff Fara on Vagueness: Sunday, April 18th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Delia Graff Fara coming to speak over dinner on vagueness in our language and concepts. Professor Fara, who focuses on philosophy of language and logic, is a leading specialist on the problem of vagueness, and in 2002 won the American Philosophical Association's prestigious "article prize" for the best journal article published by a younger scholar.

Professor Fara will be discussing the problem of vagueness. A term is vague to the extent that we find it difficult to apply it to "borderline" cases. Typical examples of vague terms include tall (at what point does someone cease being tall?), personhood (when does it start? when does it end?), and heap (how many grains of sand does it take to make a heap?). Vague terms seemingly abound in our language and thought, yet characterizing their proper application has been notoriously difficult. Indeed, vagueness seems to force upon us the so-called "sorites paradox": if no small change in a feature (e.g. number of grains of sand in the heap) can change an object's status (e.g. as a heap), then it seems hard to see how any change in a feature could change an object's status.

A number of explanations have been proposed for understanding vague terms: fuzzy logic (borderline statements have partial truth values), supervaluationism (borderline statements have no truth values), so-called glut theories (borderline statements are both truth and false), and epistemicism (borderline statements have truth values, but we can never know them). Each of these proposals has been beset by challenges. Professor Fara has developed an interest-relative approach to analyzing vague terms that emphasizes the pragmatic interests of the speaker and the use to which the term is being employed.

Location: Rockefeller College Private Dining Room.

Boris Kment on Newcomb's Problem: Sunday, April 11th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Boris Kment coming to speak over dinner on a famous thought experiment in philosophy known as "Newcomb's Problem". Professor Kment, who joined the faculty this year from the University of Michigan, specializes in modality and metaphysics.

Professor Kment will be discussing the Newcomb decision problem: You love licorice. As you are walking toward the corner store to buy a big bag of it, you suddenly remember a study you recently read: a group of scientists in Absurdistan found that those who eat a lot of licorice are one hundred times as likely to die of heart disease than the rest of us. However, correlation doesn't prove causation. In fact, the research also showed that eating licorice does not affect your health. Rather, the strong correlation between licorice consumption and heart disease is due to a common cause: people who eat licorice do so because they have a certain gene, and that gene also causes heart disease. What should you do?

If you eat the licorice, then that means you likely have the gene and will die of heart disease-a very grim prospect. On the other hand, whether or not you eat the licorice will have no effect on your heart, so why not indulge? This puzzle, called the 'Newcomb problem,' is one of the open and hotly debated issues of contemporary philosophy. We will see that it raises deep issues about the very nature of practical rationality and its relation to causation and expectation.

Location: Forbes College Special Dining Room.

Aesthetics: Tuesday, April 6th at 9:00 pm
Philosophers often study aesthetics as a window into broader philosophical questions. For instance, we typically believe that there is such a thing as "beauty" in the world, yet the property of being beautiful is also typically believed to reside not in the object itself but in the mind of the beholder. How are we to make sense of and understand the reality of such mind-dependent properties? Can they be compared across individuals? How does our appreciation for aesthetics relate to our other values?

Philosophers also use aesthetics to probe whether and how subjective value judgments can be criticized. Is aesthetic pleasure simply a brute emotional response Ð something beyond our control Ð or is it subject to some form of rational control? Can we ever say that someone is "wrong" in making aesthetic judgments? Can we "improve" our aesthetic sensibilities? Is aesthetic pleasure the most important part of our appreciation of beauty, or should we also value complexity and depth ("high-culture") for their own sakes?

Location: Tower Room, 1879 Hall.

Adam Elga on Reasoning about Fallibility: Sunday, March 28th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Adam Elga coming to speak over dinner on reasoning about one's own fallibility; the title of his discussion is "Don't trust anyone, not even yourself". Professor Elga, a specialist in reasoning and philosophy of science, is well-known for his analysis of the "sleeping beauty problem", and his "Reflection and Disagreement" was chosen by Philosopher's Annual as one of the 10 best philosophy papers of 2007. From 2004 to 2007, he held the William G. Bowen Presidential Preceptorship.

Professor Elga will be discussing how we should account for the possibility of error in our thinking. Smart people know that they sometimes make mistakes, and take this possibility into account in their reasoning. For example, they try to rely less on thinking that they did when tired, stressed-out, or otherwise impaired. But what happens when one tries to uniformly follow this advice, and put less than full trust in *all* reasoning - even reasoning about how best to take into account the possibility of making mistakes?

Location: Butler College Special Dining Room.

Metaphilosophy: Tuesday, March 2nd at 9:00 pm
Philosophers generally study three types of problems; stated simply, there are ontological, epistemic, and semantic questions. Ontology is the question of what there is in the world: what underlying substances, properties, laws, and so forth exist. Epistemology is the question of how we know about the world: this broadly subsumes philosophy of science (how science is done), theoretical rationality (reasoning about the world), and what it means to have knowledge. Finally, semantics is the question is what we mean when we use language and concepts: not what is out there in the world, but what we represent to be out there and how we represent it.

Philosophers also use a variety of evidence in solving these problems. Most (in)famously, there is philosophical intuition: a kind of rationalist, prior or introspective belief. Philosophers have also frequently deployed the tools of formal logic (in a very broad sense) to develop sophisticated theories of metaphysics, arguing that any theories of metaphysics that are logically inconsistent (or cannot be formalized) are inferior or incorrect. Some philosophers, seeking to preserve a "continuity" between philosophy and science, have also introduced experimental evidence, using psychological studies to probe semantic questions.

We will discuss the strengths and weaknesses of philosophy in general. Which problems is it best positioned to answer, and which should it cede authority to the science or some other methodology? In which domains do the various kinds of philosophical evidence carry the most weight? Are there some questions that philosophers are simply not equipped to answer except with idle speculation? Most damningly, is the only role of philosophy to disprove bad ideas, rather than generate good ones?

Location: Tower Room, 1879 Hall.

Patterns and Structural Nihilism: Tuesday, February 9th at 9:00 pm
Daniel Dennett has argued that there may be objective patterns in nature, patterns that are not merely in the eye of the behold. Specifically, if the information needed to create the pattern can be transmitted without a verbatim account of every member of the pattern, then the pattern is objective. This "compression of information" criterion could potentially serve as a response to structural nihilism, or (roughly) the claim that there is no objective structure in the world, but rather that structure is a projection of the mind.

We will discuss the extent to which it is the case that objective patterns exist, and if so whether they can serve as a device for developing a conception of reality as objectively structured.

Location: Tower Room, 1879 Hall.

Judith Jarvis Thomson on The Trolley Problem: Sunday, December 13th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Judith Jarvis Thomson coming to speak over dinner on the Trolley Problem. Professor Thomson is Professor Emeritus of Philosophy at MIT, where she previously held the Laurence S. Rockefeller Chair in Philosophy. Her 1971 essay "A Defense of Abortion" has become "the most widely reprinted essay in all of contemporary philosophy", and her 1976 paper "Killing, Letting Die, and the Trolley Problem" was responsible for popularizing the Trolley Problem, which has become one of the most discussed thought experiments in philosophy.

In light of her propensity for developing clever thought experiments, the (humorous) Philosophical Lexicon devised the following definition: "thomson gun, n. A double-barreled sniping weapon developed at M.I.T."

Professor Thomson will be discussing the famous Trolley Problem. The problem, in short, is this: we are strongly inclined to think that killing a person is worse than letting a person die - so much worse that you must not kill one person to save five people, you must, instead, let the five die. For example, you may not cut up a person who has not volunteered and use his internal parts (heart, kidneys, etc.) to save five lives. You must not knock a very heavy person off a footbridge onto the track to stop a trolley so that it does not run into and kill five people. How come, then, that so many people think you may throw a switch that will turn a runaway trolley so that it runs into one person and does not run into the five that it would otherwise run into?

Location: Butler College Special Dining Room.

Information and Representation: Tuesday, December 8th at 9:00 pm
We might say that some particular physical passage in a printed copy of a newspaper 'carries' or 'represents' information about some event. But now imagine that the newspaper is in Chinese; does it still contain information? What if the newspaper is written in some language no one understands today, but which was understood in the past? What if the passage is written in a language which no one has ever understood, but which is in principle logical? What if the passage is just a single symbol, "*"? Does this symbol count as information? Would it make any difference if in some country, "*", is a symbol well known to mean "Yesterday, in northern Siberia, Russia conducted an underground nuclear missile test."?

We will talk about the problems with claiming that information is representable (especially in a non-relativistic way) and then talk about the (potential) problems with claiming that it is not.

Location: Tower Room, 1879 Hall.

Kwame Anthony Appiah on National Culture: Sunday, November 29th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Kwame Anthony Appiah coming to speak over dinner on the idea of national culture. Professor Appiah is the Laurance S. Rockefeller University Professor of Philosophy, has previously served as the President of the Eastern Division of the American Philosophical Association, and is currently serving as the President of the PEN American Center. His work spans the gamut of formal semantics, moral theory, philosophical methodology, literary theory, and political philosophy.

Professor Appiah will be discussing the usefulness of the idea of a national culture. People often appeal to the notion of a national or ethnic culture to ground normative claims. The English Only movement, for example, claims that the English language is central to American culture and identity, and that immigrants should therefore not be permitted to use other languages in American schools or (on ballot papers) in American elections. Quebec nationalists claim that francophone culture is central to the life of their province and should, therefore, be protected by the government. And many groups over the last few centuries have argued that because they are a people with a shared culture they should be granted political self-determination.

Professor Appiah believes that these ideas have roots in philosophical theories of culture and nation that go back to the philosopher Johann Gottfried Herder, and that his picture of culture is seriously mistaken. So he will identify some of the confusions about culture that this has engendered, and clarify what culture actually means.

Location: Butler College Special Dining Room.

Topics in Philosophy of Language: Tuesday, November 23rd at 9:00 pm
One contentious debate in the philosophy of language - a debate that overlaps significantly with metaphysics - is over the notion of reference. According to the traditional theory of reference, descriptivism, to refer to a thing was merely to provide a description of it. So, for instance, when I refer to a "house", what I mean to say is "the thing that satisfies enough of the following conditions: free standing, structure, designed for residence, etc". The semantic content (meaning) of the term is exhausted by its descriptive content.

In the 1960s and 70s, however, Saul Kripke and Hilary Putnam launched a series of attacks on descriptivism that led to its widespread rejection among philosophers, and, indeed, helped to revive the discipline of metaphysics itself. They argued that the semantic content of a term is - at least in part - external to the mind that uses the term. Namely, we latch on to "natural kinds" that exist in the world; it is to those kinds that terms refer, not the properties manifested by the kinds. As a consequence of their work, they argued that there are "necessary a posteriori truths" - truths that are necessarily true, but only knowable in light of empirical experience. This finding was extremely influential in metaphysics, as it bolstered the confidence of many philosophers that metaphysics had something important to say about the world that didn't depend on (perhaps) questionable notions of conceptual truth.

We will discuss why philosophers have come to reject descriptivism in favor of semantic externalism, and what intuitions lie behind the notion of natural kinds. We will also evaluate whether Putnam and Kripke were right in their understanding of the way we use language. Finally, we will discuss the relationship between philosophy of language and metaphysics - and whether / how the latter ought to influence the former.

Location: Tower Room, 1879 Hall.

Peter Railton on Happiness and Morality: Sunday, November 15th at 6:00 pm
The Princeton Philosophical Society is pleased to have Professor Peter Railton coming to speak over dinner on the relationship between happiness, well-being, and morality. Professor Railton is the John Stephenson Perrin Professor of Philosophy at the University of Michigan, and is visiting Princeton for two weeks. He is considered one of the most important meta-ethicists in the world Ð the person who made moral realism respectable again Ð and has also done substantial work in moral theory proper.

Professor Railton will be discussing the normative implications of research into human happiness. Recent decades have seen an explosive growth in empirical psychological research into human happiness Ð its causes, consequences, and (though to a lesser extent) nature. Most of this research has focused on self-reported "subjective well-being", typically expressed in terms of momentary feelings of well-being and of overall life-satisfaction. Many people find the results of this research surprising and even paradoxical. It certainly gives us some ground for questioning our assumptions about happiness, as well as the use we make of happiness in moral theory.

He will survey some of this research, and propose an account of the nature and function of subjective well-being, which helps us make sense of many of the puzzling empirical results, and leads to some important implications for morality.

Location: Butler College Special Dining Room.

Monism: Tuesday, November 9th at 9:00 pm
Among philosophical theories of ontology - of what there is - there is a general divergence between monist theories, which say the universe is made up of only one kind of thing, and pluralist theories (such as mind-matter dualism), which say that the universe is made up of multiple different kinds of things. Many have conceptually rejected pluralism on one of two grounds (i) that it is needlessly complex, and (ii) that it cannot accommodate interaction between ostensibly different kinds of things.

There are essentially three flavors of monism: idealism, materialism, and "neutral" monism. The first says that the world is made up solely of ideas (put differently: qualia, phenomenal properties, the "what it is like"-ness of stuff), the second says that the world is made up solely of physical things (that is, more-or-less things with mass and extension), and the final says that the world is made up of some neutral substance - neither mind nor matter - that gives rise to both the physical and the phenomenal. The question we will address is whether monism is a viable alternative to pluralism and, if so, what type of monism is the best explanation of the world.

Location: Tower Room, 1879 Hall.

Frank Jackson on Conditionals: Sunday, October 25th at 6:00 pm
For our second Sunday dinner of the semester, the Princeton Philosophical Society is pleased to have Professor Frank Jackson coming to speak on conditionals. Professor Jackson, who has a half-time appointment at Princeton, is considered to be "one of the world's leading figures in metaphysics, philosophy of mind, epistemology, and metaethics (among other areas)".

Professor Jackson will be discussing conditional (if-then) statements in language and logic. Philosophers and logicians are, by and large, reasonably confident that they know what to say about conjunctions (and), negations (not), and disjunctions (or). A conjunction P&Q is true if and only if both P is true and Q is true. A negation not-P is true if and only if P is false. A disjunction PvQ is true if and only if at least one of P and Q are true.

The trouble starts with conditionals, sentences of the form 'If P then Q'. Despite their simplicity and ubiquity, and despite the efforts of some of the best philosophers and logicians over the centuries, there is no generally agreed treatment of them. Professor Jackson will give a somewhat opinionated review of the debate over conditionals. No prior reading will be assumed.

Location: Butler College Special Dining Room.

Moral Naturalism: Tuesday, October 20th at 9:00 pm
Moral naturalism is, roughly speaking, the project of placing morality into our ordinary formulation of the natural world. The aim of the moral naturalists is to reduce morality from a "spooky" concept into one that not only fits into the natural world, but is also part of the best explanation of that natural world. The typical moral naturalist will define what it is to be morally good in terms of rationally satisfying desires, and will Ð or at least, may have to Ð admit that not everyone has a reason to be moral, even though morality itself is an objective concept.

Several problems flow from this. Most obviously, it seems to be an inherent part of our conception of morality that everyone ought to be moral; that is, that everyone has a reason to be moral. More practically, we can pose the problem of moral relativism: do different groups of people have essentially different understandings of what the concept of morality is, or is there one universal sense of morality in which we all use the term? Finally, we can question whether morality is the kind of thing that can be reducibly explained by natural properties. Just as some (the dualists) argue that phenomenal qualities ("qualia") are not reducible to physical properties, is morality similarly irreducible?

Location: Tower Room, 1879 Hall.

Dan Cloud on Cancer and Capitalism: Sunday, October 11th at 6:00 pm
For our first Sunday dinner of the semester, the Princeton Philosophical Society is pleased to have Professor Daniel Cloud coming to speak on Cancer and Capitalism. Professor Cloud is a fellow in the Princeton Society of Fellows who focuses on the philosophical foundations of economics and of biology.

Professor Cloud will be discussing parallels between biology and economics. In the last few decades, evolutionary game theory has made us familiar with the idea that parallels can be drawn between biological evolution and economic or political processes in human societies. Neoplastic progression, the process by which a population of cells becomes cancerous, is an example of an evolutionary process, happening over a time-scale short enough to make it observable, in which a complex system spontaneously acquires a capacity for open-ended evolution.

A comparison will be made between this process and the spontaneous self-organization of a free society as Friedrich Hayek describes it in 'The use of knowledge in society'. Are there any significant parallels or differences between the two processes? Does the biological process shed any light on Hayek's rather paradoxical theory of the role of knowledge or information in a free society?

Professor Cloud has kindly provided us with a background reading, the short article by Hayek that he mentions.

Location: Butler College Special Dining Room.

Physicalism and Naturalism: Tuesday, September 22rd at 9:00 pm
The topic of the discussion will be the place of physicalism - an often unstated but implicit assumption of philosophical discussion - in philosophical thought. Physicalism, roughly defined, is the thesis that all that exists in the world is "physical" stuff. A frequently accepted corollary of physicalism is known as the "causal closure" of physicalism, which states that the only substances with causal efficacy (i.e. that can interact with the world) are physical substances. Physicalism, in one form or another, is accepted by many philosophers, professional and lay, but it is a problematic theory. Defining exactly what qualifies as physical is particularly vexing: defined too narrowly, physicalism seems absurd; defined too broadly, physicalism means nothing.

One very important question, then, is whether we need physicalism at all. One variant of the position known as methodological naturalism (a theory even more amorphous than physicalism) is that we need not made extensive ontological commitments (i.e. commitments about what is real) at all. That, instead, we should simply follow the scientific method of gathering evidence and using inference to the best explanation, and that there is no need to debate over whether only physical things exist or not. Naturalism is especially appealing if, in fact, debates over ontology end up lacking substance; that is, if the concept of physicalism is necessarily so broad that it has no implications.

Our primary question for discussion, then, will be this: do specific arguments about substantive ontology matter? Is it profitable to argue about exactly what substances compose the world, or do such arguments invariable devolve into empty disputes? Can we succeed by rejecting substantive ontological commitments as much as possible - as the naturalists do - and just trying to adhere the basic principles of the scientific method? Is that even possible?

Location: Tower Room, 1879 Hall.

Dichotomies in Philosophy: Tuesday, May 5th at 9:00 pm
It seems that many discussions in philosophy tend towards dichotomies. Realism vs. anti-realism in epistemology, objectivism vs subjectivism, realism vs. idealism, compatibilism vs. incompatibilism, and so forth. While by no means do all views fall into this categorization, it seems as if though many of these dichotomies are parallel Ð as if though all the latter views are more consistent with each other than with any of the former entries, and vice versa. In particular, there seems to be a tendency toward external versus internal truth in almost all subdisciplines. Is it possible there is some root intuition driving all of these dichotomies? Is there something more at play? Or is the distinction illusory?

Location: Tower Room, 1879 Hall.

Alexander Nehamas on Nietzsche: Sunday, May 3rd at 6:00 pm
For our last Sunday dinner of the semester, the Princeton Philosophical Society will be having a dinner this Sunday (May 3rd) with Alexander Nehamas. Nehamas, Edmund N. Carpenter II Class of 1943 Professor, has written groundbreaking works in ancient philosophy, Nietzsche studies, and aesthetics. His latest book, Only A Promise of Happiness, was called 2007's best scholarly book in philosophy by the Association of American Publishers, while his 1985 work on Nietzsche was called "the best and most important book on Nietzsche in English". Professor Nehamas is also universally beloved by his students, and has won several teaching awards through his career, including the University of Pennsylvania's highest teaching honor.

He will discuss the role of "perspectivism" in Nietzsche's philosophical thought, a view often described as the claim that "Every view is an interpretation." The question is often asked: Is perspectivism itself an interpretation or not? If not, then there is at least one view that is not an interpretation, and perspectivism refutes itself. If it is, then, since it is no more than an interpretation, there is no reason for us to believe it. Such considerations identify perspectivism with relativism, which claims that we have no right to speak of what is true about an issue but only of what is true for me (or for us) and is refuted in a similar way.

Is perspectivism is in fact a form of relativism? Do the refutations above in fact succeed? Professor Nehamas will argue that the answer to both is no, and that it is worth asking what the point of perspectivism could possibly be and what implications it may have for our knowledge of the world.

Location: Whitman College Private Dining Room.

Robert DiSalle on the "ineffective reasonableness of mathematics": Sunday, November 30th at 6:45 pm
We will having a special sushi dinner with visiting Professor Robert DiSalle. Professor DiSalle studies the history and philosophy of science, and specializes in the philosophical history of physics. His latest book, Understanding Space-Time, has been called "a unique and extremely valuable new addition to the philosophy of space-time physics."

DiSalle will discuss the what he calls the "ineffective reasonableness of mathematics", and its relationship to philosophical revolutions in natural science. Philosophers have traditionally puzzled over the "unreasonable effectiveness" of mathematical explanations of the physical world, but DiSalle wants to turn that observation on its head and focus on what happens when a mathematical scheme fails to explain the world. In such a case, progress depends on a philosophical revolution, that is, on a revolutionary philosophical analysis of the ways in which mathematical concepts connect with physical phenomena. An examination of these revolutions suggest novel ways of thinking about not only the relationship between mathematics and physics, but also between science and philosophy.

Location: Tower Room, 1879 Hall.

Philip Pettit on Freedom: Sunday, November 30th at 6:00 pm
Our Sunday dinner series continues with istinguished political philosopher Philip Pettit tonight. Professor Petitt is the Laurance S. Rockefeller University Professor; among other things, he has served as an advisor to the Spanish government on how political philosophy can inform policy-making.

Professor Petitt will discuss the concept of "freedom" in political philosophy, which serves as the foundation of his political theory of "republicanism".

Location: Whitman College Private Dining Room.

The Naturalist's Dilemma: Tuesday, April 7th at 6:00 pm
Philosophical naturalism has assumed an almost predominant role in our thought and discourse about metaphysics, science, and knowledge. We construct our worldviews around the explainable, observable, and rationally provable, and we demand a high standard of worldly evidence for virtually all of our beliefs. Since W.V.O. Quine's withering attack on logical positivism and the supposed disconnect between science and philosophy, philosophers have increasingly conducted themselves in the manner of scientists: proposing falsifiable hypothesis and seeking theories with explanatory power.

Yet there is a fundamental dissonance between our philosophical commitment to naturalism and our pre-philosophic beliefs about the world. On the one hand, we demand explanatory power and evidence; on the other hand, we instinctively believe in the existence of causally inert things (that is, things that don't impinge upon the natural world). Among other things, we believe in abstract objects, morality, mental substance, supernatural beings, and mind-independent truth Ð all of which are often claimed to have no physical substance or effect on the natural world.

Our knowledge of causally inert things poses troubling questions for all philosophers, not just naturalists, though the conflict there is most apparent. We would like to explore the nature of these things, and ask what implications their existence would hold. Do they even exist, or are they only apparently causally inert? How can we come to have knowledge of them if they do not impinge upon the natural world? Can we reconcile them with naturalism Ð and, if not, which do we believe more strongly in? If we accept them as real, is there any non-trivial philosophical work that can be done to describe them, or are they by nature completely elusive?

Location: Tower Room, 1879 Hall.

Peter Singer on Utilitarianism: Sunday, November 30th at 6:00 pm
Our Sunday dinner series continues with Professor Peter Singer, a world-renown moral philosopher who is one of the leading defenders of utilitarianism.

Professor Singer will be discussing the structure and nature of utilitarianism. What does it demand of us? What is the ideal form of it? What are its technical challenges? How can we be persuaded to become utilitarians? And many other matters.

Professor Singer has kindly provided us with two background readings, available here and here.

Location: Whitman College Private Dining Room.

Experimental Philosophy: Tuesday, November 24th at 9:00 pm
A popular recent development in philosophy is the use of psychological research to inform philosophical conclusions, particularly in moral philosophy. An especially influential player in this movement is Joshua Greene, who has used fMRI imaging to explore the brain activity present during moral reasoning.

Greene has advanced what he terms a 'dual process' view of moral reasoning. On this view, people use two different cognitive systems to arrive at moral decisions: one involving an immediate emotional response (a valenced system), the other involving calculation of situationally significant factors on the model of Descartes' 'pure reason' (a non-valenced system). He claims that when people reach conclusions based on consequentialist considerations, they are motivated by intellection. In cases where people go with response that is not obviously consequentialis, their intellect is overwhelmed by the emotional response.

Graduate student Rochelle Edinburg will join us to review Greene's findings. She will raise some problems with his experimental methods, and discuss some doubts about the possibility of making arguments about the reliability or choice-worthiness of certain types of moral reasoning based on fMRI or behavioral data.

Location: Tower Room, 1879 Hall.

Tom Kelly on Philosophical Radicalism: Sunday, November 16th at 6:00 pm
Our Sunday dinner series continues with Professor Thomas Kelly, a specialist in epistemology who was awarded membership in the Harvard Society of Fellows, considered the most exclusive and prestigious postgraduate fellowship in the country.

Professor Kelly will be discussing whether and to what extent it is rational for philosophical arguments to lead us to revise our ordinary, 'common sense' views about ontology, epistemology, and morality. Must we accept either the Moorean argument that common sense necessarily trumps philosophy or the Cartesian view that philosophy requires jettisoning our ordinary beliefs at the door, or is there a stable alternative? What distinguishes philosophical argument from other forms of argument that do seem to trump common sense (such as science)?

Professor Kelly has kindly provided us with a background reading, his own working paper on the topic, which may be found here.

Location: Whitman College Private Dining Room.

Gideon Rosen on Moral Responsibility: Sunday, October 27th at 6:00 pm
Our Sunday dinner series continues with Professor Gideon Rosen, who has previously been awarded the President's Award for Distinguished Teaching, Princeton's highest honor for teaching. Professor Rosen addressed us last year, and commented afterward that it was "a terrific discussion Ñ probably the best I've had with a group of undergraduates at Princeton or elsewhere."

Professor Rosen will start by talking about the moral significance of duress. We would like to identify and explain the conditions under which duress should be a legitimate excuse in morality and the law. As Rosa Brooks asks, "Is someone who kills the innocent in order to save his own life or the life of a family member morally blameworthy for his act? If not, is he merely excused (as he might be if he were temporarily insane), or is his act somehow justified or permissible?" If we ourselves are under duress, what are we to do about it and why?

He has kindly provided us with a background reading, which may be accessed here.

Location: Whitman College Octagonal Private Dining Room.

Self-Deception: Tuesday, October 7th at 9:00 pm
We frequently deceive ourselves about the state of the world: we accept beliefs in the face of strong evidence to the contrary, following our emotions and desires rather than epistemic merit. We do this in order to lie more effectively to others; to feel more confident and optimistic; and to escape unpleasant facts.

We'd like to explore this common practice from a philosophical point of view. We'd like to ask whether self-deception is intentional or non-intentional. What does it imply for our view of rationality -- and, indeed, our ability to even be rational? Perhaps most importantly, under what conditions (if any) should we be comfortable with self-deception?

An optional background reading may be found here.

Location: Tower Room, 1879 Hall.

Truth and Belief: Tuesday, September 23th at 9:00 pm
It seems apparent that one of the most important goals of philosophy is to discover truths about the world. Yet it also apparent that two fully rational individuals, given the same evidence, can properly draw two entirely different conclusions. So, for instance, Jones, who begins with weak beliefs in (a) the existence of god and (b) the conventional theory of cancer, justifiably interprets a series of a complete cancer remissions as evidence for the existence of god. Smith, meanwhile, who has weak beliefs that (a) god does not exist and (b) cancer can be cured by eating turnips grown under a certain planetary alignment, justifiably interprets these same remissions as evidence against the existence of god. They both reason correctly, yet the evidence leads them to radically different conclusions.

Thus, provided we each have different prior beliefs, it may be the case that no matter what evidence is shared among us, we will continue to disagree about the state of the world. To be sure, this is less of a problem for science, given the variety and specificity of empirical evidence available. However, this seems to be a major problem for philosophy. Debates over free will, the existence of objective morality, the existence of abstract objects, and so forth often turn more on our prior beliefs (intuitions) than upon the evidence brought to bear. It may, indeed, be the case that many problems in philosophy cannot be resolved -- that, after all the evidence is exhausted, we may justifiably maintain differing beliefs.

If we are right that fully informed and rational people can disagree, then the best philosophy might hope to do is ensure that our beliefs are self-consistent and consistent with the evidence. It will not ensure that our beliefs track the truth. Is this in fact the case? If it is, does it devalue the philosophical enterprise? What implications would it have for the way we discuss and debate philosophy? What implications would it have for the way we think about our beliefs? If we are able to extend it to cover every single belief we have, does that mean that we cannot privilege any of our beliefs as being stronger or more basic than the others?

A more formal treatment of the argument can be found here.

Location: Tower Room, 1879 Hall.

Michael Walzer on the Jewish Political Tradition: Sunday, April 27th at 6:00 pm
Our Sunday dinner series continues with Michael Walzer, of the Institute for Advanced Study, who has been called "our nation's preeminent living political philosopher" and was ranked one of the world's top public intellectuals by Prospect magazine.

He will discuss the Jewish Political Tradition, one of his enduring research projects. In particular, he'd like to use it as a jumping off platform for questions about intellectuals traditions in general. What is a tradition? How do we mark its boundaries? Who is in and who is out? What is the value of "traditional" discourse?

Location: Whitman College Octagonal Private Dining Room.

Cultural Relativism: Monday, April 21st at 9:00 pm
Cultural relativism is often taken as a given in academia. Propelled by findings of modern anthropology, it sometimes seems as if its only alternative is modern jingoism, nationalism, or an attitude of cultural superiority. But is this true? Are there general points of agreement which virtually all cultures share or should share? Or, rather, is the search for absolutes fruitless? And what of variation within a cultural itself? Can we distinguish between relativism about morality and relativism about other practices, or do we have to accept or reject relativism outright?

Location: Tower Room, 1879 Hall.

Robin Hanson on Economic Welfare and Morality: Monday, April 14th at 6:00 pm
We are pleased to present a special dinner with Robin Hanson, associate professor of economics at George Mason University, who specializes in the study of rationality and decision-making.

He will discuss the relationship between economic welfare and morality. Economists typically infer what people want from their choices, and then endorse policies expected to give everyone more of what they want. Philosophers often complain such policies are morally deficient, implicitly endorsing an implausible and crude version of utilitarianism. Professor Hanson will argue that what people want includes their moral considerations, and that he (and most of us) want policy to give us what we want, even if that is immoral.

Hanson sketches out his argument here. Background information can be found here.

No RSVP is necessary; students of all backgrounds are welcome! Please get your food from the serving area and then bring your trays into the PDR (there'll be a sign on the door). Note to juniors and seniors without a meal plan: you will have to use one of your two weekly meal passes to come to this event.

Location: Rockefeller College Private Dining Room.

Bas van Fraassen on Conflicts and Dilemmas: Sunday, April 13th at 6:00 pm
Our Sunday dinner series continues with Professor Bas van Fraassen, one of the world's preeminent epistemologists and the inaugural winner of the prestigious Lakatos Award for philosophy of science. Professor van Fraassen will be retiring at the end of the semester, so this is perhaps the last time to ever hear him speak.

He will discuss the reformative consequences of dilemmas and intellectual conflicts in both ethics and epistemology. In epistemology, we necessarily commit ourselves to particular worldviews which then structure our observations, beliefs, and theories. Yet these worldviews can be wrong. How can we make sense of accepting a new worldview when it is not a genuine option under our current one? In ethics, we sometimes face moral dilemmas; that is, there are times when we ought to do something and not do it. Such situations can motivate us to revise our moral beliefs, but the basis upon which we do so is unclear. Professor van Fraassen will examine each of these cases and then look for possible connections and parallels between them.

Background on moral dilemmas can be found here. Background on worldview change can be found here.

No RSVP is necessary; students of all backgrounds are welcome! Please get your food from the serving area and then bring your trays into the PDR (there'll be a sign on the door). Note to juniors and seniors without a meal plan: you will have to use one of your two weekly meal passes to come to this event.

Location: Whitman College Octagonal Private Dining Room.

Decision-Making Paradoxes: Tuesday, April 10th at 9:00 pm
Decision theory is the area in philosophy that studies how we ought to make rational decisions in light of our ends. Two notorious open problems in decision theory are Newcomb's problem and Kavka's toxin puzzle, each of which suggest that it might be 'rational' to be 'irrational'. We will examine each of these paradoxes in turn and consider what they have to say about rational judgement.

A brief overview of each problem may be found here (highly recommended).

Location: Tower Room, 1879 Hall.

John Gardner on Moral Luck: Sunday, April 6th at 6:00 pm
Our Sunday dinner series continues with Professor John Gardner, who is visiting Princeton this semester from Oxford University and is considered one of the world's leading legal philosophers. Professor Gardner will discuss the problem of outcome luck: that we judge actions differently based on how they turn out, rather than simply on intent. A familiar instance of the problem is found in the distinction drawn in most legal systems between attempted crimes (such as attempted murder) and their completed counterparts (such as murder). He will discuss whether there is an authentically moral explanation for the disparate treatment -- whether completed wrongs and attempted wrongs are morally distinct -- or whether such differentiation is merely prudential.

Further background information can be found here.

No RSVP is necessary; students of all backgrounds are welcome! Please get your food from the serving area and then bring your trays into the PDR (there'll be a sign on the door). Note to juniors and seniors without a meal plan: you will have to use one of your two weekly meal passes to come to this event.

Location: Whitman College Octagonal Private Dining Room.

Gideon Rosen on Philosophy of Mathematics: Sunday, March 30th at 6:00 pm
Our Sunday dinner series continues with Professor Gideon Rosen, a specialist in metaphysics who has previously been awarded the President's Award for Distinguished Teaching, Princeton's highest honor for teaching. Professor Rosen will talk about the philosophy of mathematics and why it matters. He'll present a "knock down" argument for Platonism, the view that non-physical, non-mental abstract objects exist, and then discuss the implications of this for metaphysics, epistemology, and the philosophy of language. The material is completely non-technical, so knowing basic arithmetic will suffice for understanding the argument.

Professor Rosen has kindly provided a background reading, "On What There Is" by WVO Quine.

No RSVP is necessary; students of all backgrounds are welcome! Please get your food from the serving area and then bring your trays into the PDR (there'll be a sign on the door). Note to juniors and seniors without a meal plan: you will have to use one of your two weekly meal passes to come to this event.

Location: Whitman College Octagonal Private Dining Room.

Sarah McGrath on Moral Disagreement: Sunday, March 9th at 6:00 pm
The inaugural speaker for our new Sunday dinner series will be Professor Sarah McGrath, a specialist in moral philosophy and metaphysics. Professor McGrath will discuss the the epistemic problem of moral disagreement: even if some moral facts exist, how can we ever determine what they are given the extensive degree of moral variation in the world? Are we justified in holding idiosyncratic moral values even if they are widely rejected? If half of us believe that fetuses have moral rights and half of us do not, how are we to decide who is correct? How does the moral case relate to the general problem of epistemological disagreement?

A concise summary of the basic problem can be found here. A more detailed treatment may be found here.

No RSVP is necessary; students of all backgrounds are welcome! Please get your food from the serving area and then bring your trays into the PDR (there'll be a sign on the door). Note to juniors and seniors without a meal plan: you will have to use one of your two weekly meal passes to come to this event.

Location: Whitman College Octagonal Private Dining Room.

Justice and Revenge: Tuesday, February 26th at 9:15 pm
What is justice? What is revenge? Is there a difference? Why is justice generally acceptable and revenge unacceptable? Can we define a norm that validly distinguishes between justice and revenge? Or are "justice" and "revenge" merely artificial terms we use for convenience according to our subjective beliefs?

No formal philosophical knowledge required; students of all backgrounds ware welcome.

Location: Tower Room, 1879 Hall.

Personal Identity: Tuesday, February 12th at 9:00 pm
How do we define ourselves? What separates us from the external world? Will we be the same people ten years from now as we are now? Should the contracts we make at this moment bind us in the future (that is to say, should our present selves be allowed to bind our future selves). In considering action, must we consider the 'interests' of our future selves as being distinct from our own, or are the interests of our present selves indistinguishable from the interests of our future selves.

This is a subject with broad ramifications across both metaphysics and moral philosophy and troubling implications. For example, a consideration of identity leads some philosophers to compositional nihilism -- the notion that only 'simples' of matter, like electrons and quarks, exist, while 'objects' in the ordinary sense of the word (including people) do not exist. Peter Unger famously wrote a defense of this notion with the clever title "I Do Not Exist".

Location: Tower Room, 1879 Hall.

Pleasure, Pain, and Life's Purpose: Monday, December 17th at 9:00 pm
Normative hedonism is a moral doctrine which argues that seeking pleasure and avoiding pain should be the only ends in life. Many normative hedonists would further contend that -- considering evolutionary history and practical experience -- this doctrine underlies what most people believe. Rules simply exist to advance the pleasure-pain principle and should be discarded when they don't. Is this doctrine valid? Is it implicitly accepted by such a broad audience? Can inconsistencies in intuitive moral thought be reconciled by adopting it? Why shouldn't we adopt it and how strong are the arguments for not doing so?

Students of all backgrounds are welcome; there is no prerequisite knowledge of philosophy.

Location: Frist 207. Highly recommended background reading.

Free Will and Its Critics: Tuesday, December 4th at 9:00 pm
The Princeton Philosophical Society will be holding a student discussion on free will and its critics. Questions at issue: what is free will? can our commonsense definition withstand scrutiny? is free will actually a relevant concept? is determinism compatible with free will? does indeterminism have very radical implications? can we even judge whether determinism or indeterminism are correct? does the 'truth' of free will matter to us?

Students of all backgrounds are welcome; there is no prerequisite knowledge of philosophy.

Location: Frist 114. Reading on free will.

The Ethics of War: Tuesday, November 20th at 9:00 pm
The Princeton Philosophical Society will be holding a student discussion on the ethics of war. Topics to include: what are the justified reasons for waging war? can war ever be just? are there such things as 'laws of war' and if so what should they be? is conflict an inherent part of the human condition or can it be eliminated? if it can be eliminated, should we eliminate it? at what cost?

Students of all backgrounds are welcome. There is no prerequisite knowledge of philosophy! Take note, however, that this discussion is not for the purposes of questioning whether current day wars such as the invasion Iraq are right or wrong. It is a discussion of the eternal and theoretical aspects of war and morality, which can permit but will by no means center on discussion of current events.

Location: Frist 307. Optional but useful background reading.