Suppose I say that Rembrandt's "Night Watch" is insipid, because it is too big (about 350 × 450 cms.) and its particular blocklike use of chiaroscuro makes it naive and primitive. I have made three interlocking aesthetic claims, together with an explanation of each. Now you go to have a look at the painting. You are bowled over by it, and you decide, rightly, that my aesthetic pronouncements are false, and that my explanations of them are absurd. Haven't my claims been falsified just as much as my nonaesthetic claim would have been had I said that painting is very small, about 3 × 3 cms., and you, having had a look at the painting, reported that in fact it is very large? Size can be an aesthetic property, by the way, but for the most part it is entirely non-aestheticl. Little wildflowers can be charming because of their size, e.g. wild lupins. Some houses are attractive partly because of their size.

What used to be called multiple personality disorder (MPD) is now called dissociative identity disorder (DID) in DSM, the Diagnostic and Statistical Manual of Mental Disorders , and the change in terminology may reflect a possible change in thinking. A personality (e.g. a television personality) is in one sense a person, but generally I and my personality are not the same (Same what? Same entity, presumably, if that is any help!) In any case, since my personality might change considerably over time, while I remain the same person or the same individual (I assume that individual and person , as they are applied to human beings, are equivalent concepts), the two cannot be identical. And most of us do exhibit slightly different personalities, for example at home and at work, or with friends and with superiors. Those who have a mixed ethnic or national heritage can sometimes find that they have two personalities, say one English and one Indian. They may...

How about Leslie Stevenson's Ten Theories of Human Nature ? I have had good luck teaching freshmen with this, doing a course called "Human Nature". It's on Amazon at http://www.amazon.com/Ten-Theories-Human-Nature-ebook/dp/B003F3PN1K Good luck with the class!

DNA does change. There are "point mutations", for example, in which say a single nucleotide changes, say from guanine to cytosine. . . . CTG TCA . . . becomes . . . CTG GCA . . . If there is a strand of DNA that suffers such a change, is it then not the same strand of DNA ? This is exactly like the question whether persons become different persons if they lose say half a finger. And now we have the problem of DNA identity. When are two descriptions sufficiently similar to count as descriptions of the same strand of DNA ? Anthony Quinton has the general issue right, in a 1962 article in the Journal of Philosophy called "The Soul": 'No general account of the identity of a kind of individual thing can be given which finds that identity in the presence of another individual thing within it. For the question immediately arises, how is the identity through time of the identifier to be established? It, like the thing it is...

Some random suggestions: (1) David Pears pointed out that even if Kant's argument were wholly clear and wholly successful, which it is not, it could only show that existence is not an ordinary predicate, if it is a predicate. His view is that it is a predicate, just a very peculiar one; (2) There is also the view of the celebrated logician, mathematician and philosopher Bolzano, who writes in the Theory of Science ("Kinds of Propositions") that 'I take being [Sein] or actuality [ Wirklichkeit ] to be precisely what language makes it out to be, namely an attribute; whoever denies this confuses (I believe) actuality with substance. By substance I mean an actuality which is not an attribute of another actuality; hence I admit that we cannot truly predicate the putative abstractum of the substance (substantiality) of any object. For it is part of the concept of substance that there is no property of this kind. But it is not the same with actuality, which I consider to be a mere attribute, not...

You are absolutely right. Neither colour nor a colour is spatially extended, and a colour like pink is exactly not like a gas that fills up a volume or spreads itself, perhaps very very thinly, over a surface. That is a category mistake. Nor do colours have thicknesses. I am delighted to see a recognition of this important point, to which I have found very little attention paid in the literature on the philosophy of colour. Though I tried to get started sorting out the tricky logic of "pure" colours, as Wittgenstein calls them (to be contrasted not with impure colours but with things coloured the colours), in Chapter 7 of Colour: a Philosophical Introduction , published in 1987 and 1991, but that was only a beginning. Consider two patches of the same red, patch A surrounded by green and patch B surrounded by red. We can say that the colour of patch A is identical with the colour of patch B. But then as G.E. Moore pointed out (in his early paper on "Identity") it follows, or seems to,...

Your argument is: (1) Our senses and perception are subjective. (2) Everything we know is based on on our senses and perceptions. Therefore (3) Everything we know is subjective. There is a well-known difficulty with this argument. It equivocates on "subjective". In the first premise "subjective" means something like the innocuous "possessed by a subject", but in the conclusion it is presumably taken to mean the toxic "not having any objective truth". There is also a doubt about the second premise. Many philosophers accept the idea of "a priori" truths, that is, truths that hold independently of experience, including mathematical truth and perhaps ethical truths, if there are any.

Is the idea of backwards causation coherent? It seems not, as you could, for example, cause earlier events, such as your own birth, not to have happened. There is also the famous "bilking" (cheating) argument due to Max Black, according to which you can prevent the future cause of something that has already happened from occurring. All the same, philosophers, particularly Michael Dummett, have taken the idea perfectly seriously, and defended it. You write that you doubt that a scientist would take the idea seriously, but plenty of physicists, including Richard Feynman, have indeed used the idea for a variety of purposes, including the remarkable idea of positrons running backwards in time.

Colour relationalism tells us that colours are relations between perceivers and the objects that they perceive. (This gets a bit tricky of course if what they perceive is a colour, because then what they perceive is a relation between themselves and a relation between themselves and a colour, or rather, a relation between themselves and a relation between themselves and a relation between themselves and a colour.) "Colour phenomenology" doesn't mean an awful lot: just the (apparently) obvious facts about colour and classifications of things having to do with colour based on these facts. Phenomenology in this sense has seemed to oppose colour relationalism. We don't seem to see relations between ourselves and tomatoes when we see red tomatoes. What we see is a property flattened on to the surface of the tomato! So colour relationalists have to work a bit to square their view with the phenomenology. Without meaning to be rude, might I inquire whether this is an essay topic you have been set? Why are you...

What you describe is one response (one that has occasionally been used by theists) to the problem of evil. It is sometimes called the "contrast" argument. It is found for example in Leibniz's Theodicy of 1810, in various forms, along with other arguments defending theism. The version that you propose is that evil must exist for there to be an understanding of good. In some versions of the contrast argument, evil must be there if good itself is to exist. I think it is possible however to have a very good understanding of something positive (the positive numbers, for example) without understanding something negative. Again, I can perfectly well enjoy a good ice cream without ever having tasted a bad one, and know that it is good, at least in the sense that I enjoy it. I don't think that I myself have ever had a bad ice cream, rather than the odd less than perfect one, though I may be wrong, but in any case my enjoyment of all the good ones would be much the same even if I had had a bad...