The most natural answer is probably four: the atoms A, B and C, and the dyadic 'molecule' A+B. Naïve common sense apparently has it that small things sometimes come together to form larger things. Common sense does not deliver an explicit rule or principle governing composition. But it does have firm opinions about particular cases.The particles in a chemical atom, the cells in your body, the cards in a house of cards, the stars and planets in the Milky Way galaxy:-by commonsensical standards these are all cases in which several things compose a single thing. The connection between A and B in our example is meant to be an example of the sort of relation that suffices for composition by commonsensical standards, whereas A and C are supposed to be so completely loose and separate as to compose nothing (or at any rate, nothing worth mentioning) by those same standards.Common sense about composition is opposed on both sides by distinctively philosophical approaches to the topic. Certain highly restrictive theories of composition claim that common sense is much too liberal. In his closely argued book, Material Beings, Peter van Inwagen defends the view that several things compose a single thing only when their activity constitutes the life of an organism. 1 On this view, the cells in your body -or the perhaps better, the elementary particles in your body -do indeed compose a single thing, namely you. But when the chemist says that three quarks together make a proton, or when the cosmologist says that billions of stars and planets and specs of interstellar dust together make up the Milky Way, or when the voice of common sense says that twenty cards make up a house of cards -what they say is false, strictly speaking. There are no protons or galaxies or houses of cards. There are rather billions of simple particles arranged proton-wise and galaxy-wise and house-of-cardswise. The most radical view of this sort is compositional nihilism, according to which there is no such thing as a composite entity. On this view, it is probable that you do not 1 Peter van Inwagen, Material Beings Cornell University Press, 1990. 3 exist. You just might be an absolutely simple Cartesian soul. But if not -if the only objects in your vicinity are material objects -then strictly speaking, there is no such thing as you. There are rather many simple things arranged 'person-wise' and engaged in various collective activities. Since you are not any one of these particles, and since there are no other candidates, the compositional nihilist maintains that strictly speaking, you do not exist. 2 (Which is not to say that he is chauvinistic; he says the same about himself.)In any case, compositional nihilism and van Inwagen's 'organicism' reject the natural answer to our question. They say that there are only three things in R, and in particular that the alleged complex A+B does not exist.Nihilism and organicism are minority opinions. But the commonsensical answer to our question is equally at odds with the most widely accepted philosophical theory of ...
