If any young person of leisure were so much at a loss as to ask advice as to what he should read, mine should be exceedingly simple: Read anything bearing on a definite object. Let him take up any imaginable subject to which he feels attracted, be it the precession of the equinoxes or postage stamps, the Athenian drama or London street cries; let him follow it from book to book, and unconsciously his knowledge, not of that subject only but of many subjects, will be increased, for the departments of the realm of knowledge are divided by no octroi. He may abandon the first object of his pursuit for another; it does not matter, one subject leads to another: he will have learnt the habit of acquisition; he will have gained that conviction of the pricelessness of time which stirs a sigh as each day comes to its close.
From “The Craving for Fiction,” an essay in Post meridiana: Afternoon Essays, by Sir Herbert Maxwell (1895)
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According to Wikipedia, “The Rt. Hon. Sir Herbert Eustace Maxwell, 7th Baronet of Monreith, KT, PC, FRS, FRGS (8 January 1845 – 30 October 1937) was a Scottish novelist, essayist, horticulturalist and Conservative politician who sat in the House of Commons from 1880 to 1906.