About 80 b.c., Sertorius, being for a time driven from Spain by the forces of Sulla, fell in, when on an expedition to Baetica, with certain sailors who had just returned from the “Atlantic islands,” which they described as two in number, distant 10,000 stadia from Africa, and enjoying a wonderful climate. The account in Plutarch is quite consistent with a previous knowledge of the islands, even on the part of Sertorius. Be this as it may, the glowing praises of the eye-witnesses so impressed him that only the unwillingness of his followers prevented his taking refuge there. Within the next few years, the Canaries, at least, became well known as the Fortunatae Insulae; but when Horace, in the dark days of civil war, urged his countrymen to seek a new home across the waves, it was apparently the islands of Sertorius that he had in mind, regarding them as unknown to other peoples.[312]
As we trace the increasing volume and extent of commerce from the days of Tyre and Carthage and Alexandria to its fullest development under the empire, and remember that as the drafts of luxury-loving Rome upon the products of the east, even of China and farther India, increased, the true knowledge of the form of the earth, and the underestimate of the breadth of the western ocean, became more widely known, the question inevitably suggests itself, Why did not the enterprise which had long since utilized the monsoons of the Indian Ocean for direct passage to and from India essay the passage of the Atlantic? The inquiry gains force as we recall that the possibility of such a route to India had been long ago asserted. Aristotle suggested, if he did not express it; Eratosthenes stated plainly that were it not for the extent of the Atlantic it would be possible to sail from Spain to India along the same parallel;[313] and Strabo could object nothing but the chance of there being another island-continent or two in the way,—an objection unknown to Columbus. Seneca, the philosopher, iterating insistence upon the smallness of the earth and the pettiness of its affairs compared with the higher interests of the soul, exclaims: “The earth, which you so anxiously divide by fire and sword into kingdoms, is a point, a mere point, in the universe.... How far is it from the utmost shores of Spain to those of India? But very few days’ sail with a favoring wind.”[314]
Holding these views of the possibility of the voyage, it is improbable that the size of their ships and the lack of the compass could have long prevented the ancients from putting them in practice had their interest so demanded.[315] Their interest in the matter was, however, purely speculative, since, under the unity and power of the Roman empire, which succeeded to and absorbed the commercial supremacy of the Phœnicians, international competition in trade did not exist, nor were the routes of trade subject to effective hostile interruption. The two causes, therefore, which worked powerfully to induce the voyages of Da Gama and Columbus, after the rise of individual states had given scope to national jealousy and pride, and after the fall of Constantinople had placed the last natural gateway of the eastern trade in the hands of Arab infidels, were non-existent under the older civilization. It is certain, too, that the ancients had a vivid horror of the western ocean. In the Odyssey, the western Mediterranean even is full of peril. With knowledge of the ocean, the Greeks received tales of “Gorgons and Chimeras dire,” and the very poets who sing the beauties of the Elysian or Hesperian isles dwell on the danger of the surrounding sea. Beyond Gades, declared Pindar, no man, however brave, could pass; only a god might voyage those waters. The same idea recurs in the reports of travellers and the writings of men of science, but here it is the storms, or more often the lack of wind, the viscid water or vast shoals, that check and appall the mariner. Aristotle thought that beyond the columns the sea was shallow and becalmed. Plato utilized the common idea of the mudbanks and shoal water of the Atlantic in accounting for the disappearance of Atlantis. Scylax reported the ocean not navigable beyond Cerne in the south, and Pytheas heard that beyond Thule sea and air became confounded. Even Tacitus believed that there was a peculiar resistance in the waters of the northern ocean.[316]
Whether the Greeks owed this dread to the Phœnicians, and whether the latter shared the feeling, or simulated and encouraged it for the purpose of concealing their profitable adventures beyond the Straits, is doubtful. In two cases, at least, it is possible to trace statements of this nature to Punic sources, and antiquity agreed in giving the Phœnicians credit for discouraging rivalry by every art.[317]
To an age averse to investigation for its own sake, ignorant of scientific curiosity, and unimpelled by economic pressure, tales like these might seem decisive against an attempt to sail westward to India. Rome could thoroughly appreciate the imaginative mingling of science and legend which vivified the famous prophecy of the poet Seneca:
Venient annis saecula seris
Quibus Oceanus vincula rerum
Laxet, et ingens patebit tellus
Tethysque novos deteget orbes
Nec sit terris ultima Thule.[318]
But even were it overlooked that the prophecy suited better the revelation of an unknown continent, such as the theory of Crates and Cicero placed between Europe and Asia, than the discovery of the eastern coast of India, mariners and merchants might be pardoned if they set the deterrent opinions collected by the elder Seneca above the livelier fancies of his son.[319]
The scanty records of navigation and discovery in the western waters confirm the conclusions drawn from the visions of the poets and the theories of the philosophers. No evidence from the classic writers justifies the assumption that the ancients communicated with America. If they guessed at the possibility of such a continent, it was only as we to-day imagine an antarctic continent or an open polar sea. Evidence from ethnological comparisons is of course admissible, but those who are best fitted to handle such evidence best know its dangers; hitherto its use has brought little but discredit to the cause in which it was invoked.
The geographical doctrines which antiquity bequeathed to the Middle Ages were briefly these: that the earth was a sphere with a circumference of 252,000 or 180,000 stadia; that only the temperate zones were inhabitable, and the northern alone known to be inhabited; that of the southern, owing to the impassable heats of the torrid zone, it could not be discovered whether it were inhabited, or whether, indeed, land existed there; and that of the northern, it was unknown whether the intervention of another continent, or only the shoals and unknown horrors of the ocean, prevented a westward passage from Europe to Asia. The legatee preserved, but did not improve his inheritance. It has been supposed that the early Middle Ages, under the influence of barbarism and Christianity, ignored the sphericity of the earth, deliberately returning to the assumption of a plane surface, either wheel-shaped or rectangular. That knowledge dwindled after the fall of the empire, that the early church included the learning as well as the religion of the pagans in its ban, is undeniable; but on this point truth prevailed. It was preserved by many school-books, in many popular compilations from classic authors, and was accepted by many ecclesiastics. St. Augustine did not deny the sphericity of the earth. It was assumed by Isidor of Seville, and taught by Bede.[320] The schoolmen buttressed the doctrine by the authority of Aristotle and the living science which the Arabs built upon the Almagest. Gerbert, Albert the Great, Roger Bacon, Dante, were as familiar with the idea of the earth-globe as were Hipparchus and Ptolemy. The knowledge of it came to Columbus not as an inspiration or an invention, but by long, unbroken descent from its unknown Grecian, or pre-Grecian, discoverer.