The types of dilemma you mention are good starting points for a positive moral theory. Our pre-reflective moral practice contains elements (rules of thumb, behavioral inclinations, moral intuitions and so on) that pull us in different directions in such cases; and a considered moral theory must somehow resolve such tensions if it is to be consistent. But what type of resolution is required? Suppose that we've arrived at a theoretical resolution to one of your dilemmas. For example, we decide that, on reflection, it is impermissible to inflict unnecessary suffering on sentient beings. (A full moral theory will have to contain much more than just this one principle; and I'm not, in any case, advocating this one (though it seems right to me).) This principle would rule out the eating of factory farmed animals, but not all abortions--for example, the many abortions that (a) do not involve a sentient being (as opposed to a potentiallly sentient being) or (b) might greatly decrease overall suffering (on the...

Rats are cuddly. I mean...cats are, but I typed an 'r' instead of a 'c'. Or was I temporarily misguided about the names of certain small mammals? In any case, I said something I didn't intend. Sorry. But why should we judge that I said that rats are cuddly instead of judging that I said that cats are cuddly in an idiolect which uses 'rats' to pick out cats? The answer arguably comes in two stages: first, 'rats' picks out rats in English because there is an established convention to use that squiggle and those sounds to pick out rats, and this 'rat'-rat convention originated in and is sustained by the intentions (most of them merely implicit) of a community of speakers to employ this convention. Second, my utterances are to be interpreted according to this convention because I have entered into a situation in which what I say is goverened by the English language (which contains the 'rat'-rat convention even if I don't realize it). This account of how we can say something we don't intend is certainly...

Some philosophical issues are resolved, but many aren't--often the deepest ones. Philosophers nevertheless pursue abstract and difficult issues in the hope of solving them. And this isn't clearly misguided: a low success rate might result from the difficulty of the problems instead of from their in-principle unsolvability. Still, even if some enduring problems--the mind-body problem, the nature of free will, our knowledge of the external world, and so on--are not, in fact, completely resolvable, a lot is to be learned about the nature of mind, freedom, knowledge and also rationality by pursuing them anyway. And the pursuit is independently enjoyable and edifying. Or so I have found.

I agree fully with all that Alex has said, but would add that the dizzying, off-the-rails experience that philosophical speculation can induce even in those of us who are middle-aged is, in my experience, one of the great joys of philosophy--the very reason for engaging in it. That sense that even the most fundamental assumptions of our daily life are open to refinement, speculation and even doubt is what makes the practice so exciting...even if, like many exciting activities, it sometimes makes you ill.

Any answer to the mind-body problem struggles to account plausibly for the causal relations that seem obviously to run in both directions between mind and body. For the dualist, who holds that mental states and physical states are distinct, your question is accute: how could a mental state really cause a physical state if physical states bring about one another comprehensively (or even deterministically). The effects of a given mental state seem pre-empted by the physical state that corresponds with it. Some dualists--"epiphenomenalists"--embrace this problem and hold that mental states, though caused, are themselves causally ineffective. But many have found this problematic: for one thing it's unclear how we could know about mental states (or any entities) that have no causal effects; more damaging, though, is just the sense that this does a deep injustice to the way our mental states present themseleves to us from the inside. You seem to experience mental causation consciously when you decide to...

Yes, some of it can, even in its liquid state--if it rises to the top of a volume of water and stays there, and if that's what you mean by "floating in water". Doesn't hotter water tend to do this? All bets are off if you require that at least part of a thing rise above the surface of the volume in order for it to "float in water". I'm not moved much by the "entity in its own right" worry: some molecules , bits , portions or regions of water can float in others; and maybe some kinds of water float in others, just as some gases sink in others. This answer is particularly compelling once someone reminds us of the obvious...

Dear C, Causal responsibility or moral responsibility? Causal: Yes, A's actions were crucial in the causal-chain that brought about C's harm; were it not for A's actions, C (probably) would not have been harmed by B in that way. Moral: No, at least not as you've described things. A didn't wish or intend any harm to C, and, indeed, reasonably thought that bringing B and C together would be mutually beneficial. Too bad B turned out to be a bad egg, but that's not A's (moral) fault. Upshot: Moral responsibility implies causal responsiblity, but not vice versa. (Well, this case establishes the "not vice versa" part.) No doubt some clever philosopher will try to refute all that I've just demonstrated, but don't believe her. I am off the hook. Beneficently yours, A

No, of course not! ...or so I first thought; but then your argument moved me; but now I again think... No, of course not! A's first punishment was probably unjust--certainly unfortunate. But if A now kills B, then A should be punished anew on any of the four halfway-plausible and at-least-sometimes-applicable justifications for punishment that I can think of. Deterrence: If we don't punish A anew, then we'll experience a crime-wave of similarly pardoned ex-cons (assuming certain ugly things about human nature). Rehabilitation: Well, incarceration didn't exactly work any criminal tendencies out of A, did it? (And it doesn't generally seem to accomplish much rehabilitation, at least in the U.S. .) But if incarceration would promote rehabilitation, which A surely needs, then A should be incarcerated. Public safety: Things didn't go so well when A was let out, so we're all better off keeping him in the slammer. Retribution: Here's where your...

Suppose that colors have a fourth dimension to which we, humans, are not sensitive. As a matter of fact, I gather that this is true, and that certain birds are now thought to be sensitive to just such an additional dimension. I don't see why this would challenge the existence of the colors we now see. The colors are there, it's just that we're not sensitive to all their aspects. But this answer assumes a sort of "color objectivism"--that is, that colors are properties out there in the world (certain reflectance patterns perhaps) that obtain independently of our seeing them. Suppose instead that we think of colors more subjectively, as existing in our minds--perhaps as qualitative features of our color-experiences. (I don't think this is the correct way to think of colors, but others do, and certainly some of our color-talk seems to embody this view.) If we think of colors this way (call them "subjective-colors"), then the subjective-colors of the birds--what it's like to have their color-experiences-...

There are tensions here, I agree, though I think they reside in the way that we talk about appearances rather than in the appearance/reality distinction itself--at least as it applies to cars. Size is an intrinsic property of a car if any property is--that is, a car's size, like its shape, depends entirely upon the way it alone is, and not upon what may or may not hold in the world around it. Apparent-size, by contrast, is a non-intrinsic or relational property of a car, and subtly so: a car's apparent-size depends not just upon the car's size, but also upon the relative location of the relevant viewer. Thus, the car's apparent-size (to Fred) can shrink if the car shrinks in size, but also (and using less magic) if Fred and the car move apart so that light from the car subtends a smaller angle in Fred's visual field (as they say). So, one and the same real car can consistently maintain its size and change its apparent-size through changes only in the relative position of the viewer. This is...