From Alain by André Maurois:

His third secret: reading. There was never such a reader as Alain. He read and re-read. Not a great number of authors. He cared nothing for the tyranny of fashion, but remained steadfastly attached to the few spirits that had never failed him. Philosophers: Plato, Spinoza, Descartes, Hegel, Auguste Comte. A few poets: Homer, Hugo, Claudel, Valéry. A few novelists: Stendhal, Balzac, Tolstoy, Kipling and – coming nearer our own times – Proust. A few memoir-writers: Retz, Saint-Simon, Chateaubriand, Napoleon. And then Montaigne, Rousseau, Voltaire. The thing is that he always remained a man of few books, but that he had explored his favourites to the very depths.