I doubt telepathy is possible, as I can't figure out any causal mechanism to make it work. But that's an empirical matter. I'm reluctant to rule it out in any a priori sense. Must one "know" that the content of a telepathic event is some specified other's thought or mental state? Suppose I'm reading an e-mail or engaged in Instant Messaging with someone. Clearly, I am in some sense apprehending their thoughts (or at leat their words). I do so, however, even if I don't know who the other person is, even if I'm mistaken about who it is, etc. Perhaps, someone has hacked into my friend's IM account or is impersonating my friend in an e-mail. So what? The words I apprehend remain meaningful. In the case of telepathy, one worry (as you point out), however, is that the supposed telepath might simply be apprehending her own thoughts and attributing them to others. But couldn't it go the other way, too? Couldn't one apprehend another's thought and mistakenly take it for one's own? If so, then one could...

This dimension of Socrates' thought has been, of course, highly influential with skeptics. Indeed, it was in part on the basis of this sort of gesture in Plato's works that the Academic skeptics regarded themselves as inheritors of Platonic philosophy. Later the idea became known as "learned ignorance," for example in Nicholas of Cusa's work by the same name. It's an interesting thing to examine the different ways philosophers have tried to cope with the constellation of ideas involved with coming to understand one's ignorance, as well as other dimensions of human finitude. Hellenistic and Greco-Roman skeptics explored the ways in which doubt my characterize humanity's relationship to knowlegdge and whether skeptical arguments advance any positive wisdom or simply tear things down. Montaigne formulated the now-classic, "What do I know?" Erasmus called himself a "foolospher." Hume explored concepts of "natural," "common," ordinary, and non-dogmatic forms of belief while still acknowledging skeptical...

There is no single answer to this question, just as there is no best life. There are many good lives, and many fitting each of these descriptions. Different characters will find different lives good. For myself, I say, on balance the latter is to be preferred. I find myself in agreement with the ancient Epicureans that most agitating passions produce more unhappiness than happiness, and that easy natural pleasures are better than artificial dynamic pleasures. Tranquility punctuated by ecstatic moments looks pretty good from where I sit.

An important philosophical consideration here before you get going on this issue is deciding what you mean by a group. In particular, you might consider whether you buy into what's been called methodological holism which means here, basically, that the whole is more than the sum of its parts. So, an economic class, a nation, a people, a family is more than just the individuals that compose it. Methodological individualism holds just the opposite, namely that the whole is nothing more than the sum of the parts. Would you say that the state is a group? Then, certainly, there are things that this group can do that would be immoral if performed by an individual. For example: imprison people, judge and punish criminals, conduct wars, appropriate property and tax, marry, etc.

The old principle of liberty that one can do what one likes so long as it doesn't harm others (famously formulated by John Stuart Mill) is challeneged by this sort of issue. What if someone consents to being harmed or even asks to be harmed? Can one consent to be another's slave? My view is that liberty has been found to be such a good thing that it should be maximized. But it does have limits. Sometimes those limits have to do with advancing collective, social, or political goods, like education and equality. Sometimes they involve protecting people from themselves. Why should people be protected from themselves? Because our actions towards ourselves as well as towards others are not matters of simple will disconnected from the structures of character, coercive power relationships, psychological manipulation and pathology, deceit, and plain old stupidity. On this score, I vote for maximal sexual liberty. And so I support undermining compulsory heterosexuality, compulsory binary relationships,...

May I weigh in a bit? I think that panelists are right to suggest that while the dream argument addresses the veracity of perception about the world, the demon argument goes farther and addresses mathematical and logical inferences. I'd like, however, to return to Peter Lipton's question about why the cogito survives the demon argument. There's a bit more to say on that score that explains Descartes's position. There's a difference between mathematical and logical inferences and the cogito, and that is that what Descartes finds persuasive about the cogito is not a matter of inference but rather direct intuition. The demon argument works but pointing out that in any discursive movement of thought, from one idea to another, the demon might interfere. Discursive thought, therefore, is dubious. N.B. that's why the example Alexander George quotes is about discursive movements like "adding" and "counting." In this way, Descartes anticipates, in a way, the point Quine makes in his article, "Two...

No, it can't be morally justified. Frankly, that's all that really need be said. Indeed, I must say I find asking the question today in a serious way to itself be morally unjustifiable. It suggests a kind of negligence with regard to learning about the moral accomplishments of our civilzation, or perhaps a debasement of our moral fiber. I suppose it's like asking whether genocide can be justified or whether torture and secret detention without review, trial, or warrant can be justified (!). So, to be charitable, I must conclude that you're really not asking this question in a serious way but, rather, as a kind of intellectual exercise. Briefly, then, let me suggest why slavery can't be justified by some of the central ethical frameworks philosophers have developed: 1. Virtue ethics. Slavery (as it was practiced in North America and the Carribean by Europeans--Roman slavery might have a slightly different inflection here) can't be justified since it inhibits development of the excellences and...

Yes, I think we do--generally speaking. For this reason, one of the purposes of philosophical interrogation of the concept of "race" must be to undermine it. In my teaching I try to do this where possible, and in ordinary conversation I have been experimenting with either trying to avoid racial terms altogether or using "lighter-skinned" and "darker-skinned" as descriptive terms. These terms, unlike "black" or "white" are comparative and suggest gradations and continuity (which I think accurate to the biological facts of the matter). Ethnic terms like "African" are useful, too, but don't quite bear the same force of inclusion and continuity. Nevertheless, I don't think their use terribly pernicious, except when their use is exceptional. That is, using ethnic rather than racial terms may sometimes still serve to "other," separate, subordinate, etc. when members of other groups are not desgnated with ethnic terms. There are situations, however, where using the concept of race can serve morally...

I am not a physicist, so I cannot state definitively the results that natural science has achieved with regard to this question. I can say conceptually that "largest" and smallest conceptually both define limits and are comparative--unlike "larger" and "smaller," which are comparative but don't require limits. It's also important to define "thing" (which here is rather vague), since 'largest' and 'smallest' are context-dependent. One might speak of the largest material object in spatial dimensions, the object with the largest mass, the largest jury award in a civil suit, the largest amount of memory in a single computer, the largest brawl on record, the largest number ever counted. I can also speak a bit more cogently out of 18th-century debates about whether or not material things or space are divisible ad infinitum or not ,as well as whether the universe is infinite or not. Some, like Kant, have held that reason can't determine answers to questions like this; this question is what he calls an...