Existence and Categories
"Personal Letter", David Hume to John Stewart (1754).
I never asserted so absurd a Proposition, as that any thing might arise without a Cause: I only maintained, that our Certainty of the Falsehood of that Proposition proceeded neither from Intuition nor Demonstration; but from another Source.
St. Thomas Aquinas (Random House: 1956), p. 121.
Against all this the philosophy of St. Thomas stands founded on the universal common conviction that eggs are eggs. The Hegelian may say that an egg is really a hen, because it is a part of an endless process of Becoming; the Berkeleian may hold that poached eggs only exist as a dream exists; since it is quite as easy to call the dream the cause of the eggs as the eggs the cause of the dream; the Pragmatist may believe that we get the best out of scrambled egos by forgetting that they ever were eggs, and only remembering the scramble. But no pupil of St. Thomas needs to addle his brains in order adequately to addle his eggs; to put his head at any peculiar angle in looking at eggs, or squinting at eggs, or winking the other eye in order to see a new simplification of eggs. The Thomist stands in the broad daylight of the brotherhood of men, in their common consciousness that eggs are not hens or dreams or mere practical assumptions; but things attested by the Authority of the Senses, which is from God.
"Against Materialism" in The Waning of Materialism, eds. Robert C. Koons and George Bealer (Oxford University Press: 2010), p. 7.
A second sort of defense in favor of materialism appeals to the general idea of naturalism. Here again we have a view, like materialism itself, to which many, many philosophers pay allegiance while offering little by way of clear argument or defense, but here the view itself is much harder to pin down in a precise way. Indeed, even more striking than the absence of any very clear arguments is the fact that many recent philosophers seem so eager to commit themselves to naturalism — to fly the naturalist flag, as it were — while showing little agreement as to what exactly such a commitment involves. Thus naturalism seems to be even more obviously an intellectual bandwagon than materialism. (In addition, naturalism, for some of those who use the term, seems to just amount to materialism, which would make an argument from naturalism to materialism entirely question-begging.) ¶ Is there any genuine support for a materialist presumption to be found in the vicinity of naturalism? One version of naturalism is the idea that metaphysical issues — or philosophical issues generally — should be dealt with through the use of the methods of natural science. If this is accepted, and if it is true that following the methods of natural science leads plausibly to an endorsement of materialism, then at least some presumption in favor of materialism might follow. But both of the needed suppositions are in fact extremely dubious, to say the least. There is simply no good reason to think that the methods of natural science exhaust the methods of reasonable inquiry — indeed, as has often been pointed out, there is no plausible way in which that claim itself can be arrived at using those methods.
"Cleanthes to Demea", in Dialogues Concerning Natural Religion (1779), Part IX.
In such a chain, too, or succession of objects, each part is caused by that which preceded it, and causes that which succeeds it. Where then is the difficulty? But the WHOLE, you say, wants a cause. I answer, that the uniting of these parts into a whole, like the uniting of several distinct countries into one kingdom, or several distinct members into one body, is performed merely by an arbitrary act of the mind, and has no influence on the nature of things. Did I shew you the particular causes of each individual in a collection of twenty particles of matter, I should think it very unreasonable, should you afterwards ask me, what was the cause of the whole twenty. This is sufficiently explained in explaining the cause of the parts.