Montaigne, the best notion of Seneca and Plutarch will be formed by remembering that his essays are admitted by himself to be “wholly compiled of what I have borrowed from them.”  The elder Pliny supplies us with extracts and summaries of the knowledge or the notions then extant, and we have writings on agriculture by Columella.  The youthful and rather awkward satirist Persius sees the life which he criticises rather through the medium of books than through his own eyes.  Such works of the period as have gained any kind of immortality are certainly interesting and often instructive, but they indicate a period in which reading is chiefly cultivated amusement, and knowledge rather sought as a pastime and an accomplishment than as a power.  The favourite reading must contain matter or sense, not too deep or exacting; and it must possess a style.  Perhaps writers as various as Dryden, Pope, Horace Walpole, Samuel Johnson, De Quincey, Macaulay, or, on a lower platform, the authors of collections like the Curiosities of Literature would have been quite at home in this period:  but it would have produced no Shakespeare, Milton, or Wordsworth.  The agreeable poem, the well-expressed essay, are the approved reading for men of indolent bent:  the informative collection for the more curious, serious, or practical-minded.  If the early empire is “despotism tempered by epigram,” it is perhaps not altogether untrue that the contemporary literature was pedantry tempered by epigram, or at least by quotation.

Science, though its matter was attractive enough to the practical Roman, was at a standstill.  So far as it existed it was Greek.  The Greeks had done almost all that could be done by sheer brain-power and acumen.  They could hardly proceed further without those finer instruments which we possess, but which they did not.  Though they knew of certain magnifying glasses, they had no real telescopes or microscopes, no mariner’s compass or chronometers, no very delicate balances.  They possessed a magnificent thinking apparatus and put it to admirable use.  The modern scientist has generally nothing but admiration for their keen insight, and for the brilliant hypotheses which they invented and which were frequently but unverified anticipations or partial anticipations of theories now in vogue.  Where they stopped short was at experiment in test of hypothesis.  Of all exploits of pure thinking in the domain of science perhaps the greatest has been the conception that the earth, instead of being a flat disk, is a sphere.  This theory was held before the age of Nero by ancient astronomers and geographers, who had derived the notion partly from the eclipses of the moon—­of which they well understood the cause—­and partly from the rising of objects above the horizon.  They understood also that in a sphere there was gravitation to the centre, and were able so to comprehend the level surface of water on the globe.  The geographer Strabo, more than a generation before our chosen date,