“[S]ome of you might say, as many people do: “Aw, I never think in such abstract terms — I want to deal with concrete, particular, real-life problems — what do I need philosophy for?” My answer is: In order to be able to deal with concrete, particular, real-life problems — i.e., in order to be able to live on earth.
You might claim — as most people do — that you have never been influenced by philosophy. I will ask you to check that claim. Have you ever thought or said the following? “Don’t be so sure — nobody can be certain of anything.” You got that notion from David Hume (and many, many others), even though you might never have heard of him. Or: “This may be good in theory, but it doesn’t work in practice.” You got that from Plato.
Or: “That was a rotten thing to do, but it’s only human, nobody is perfect in this world.” You got that from Augustine. Or: “It may be true for you, but it’s not true for me.” You got it from William James. Or: “I couldn’t help it! Nobody can help anything he does.” You got it from Hegel. Or: “I can’t prove it, but I feel that it’s true.” You got it from Kant. Or: “It’s logical, but logic has nothing to do with reality.” You got it from Kant. Or: “It’s evil, because it’s selfish.” You got it from Kant.
Some people might answer: “Sure, I’ve said those things at different times, but I don’t have to believe that stuff all of the time. It may have been true yesterday, but it’s not true today.” They got it from Hegel. They might say: “Consistency is the hobgoblin of little minds.” They got it from a very little mind, Emerson. They might say: “But can’t one compromise and borrow different ideas from different philosophies according to the expediency of the moment?” They got it from Richard Nixon — who got it from William James.
Now ask yourself: if you are not interested in abstract ideas, why do you (and all men) feel compelled to use them? The fact is that abstract ideas are conceptual integrations which subsume an incalculable number of concretes — and that without abstract ideas you would not be able to deal with concrete, particular, real-life problems. You would be in the position of a newborn infant, to whom every object is a unique, unprecedented phenomenon. The difference between his mental state and yours lies in the number of conceptual integrations your mind has performed.” – Ayn Rand, Philosophy: Who Needs It