The admiral being much delighted with the relations of sea voyages, his mother-in-law gave him the journals and sea charts which had been left by her husband, which excited his curiosity to make inquiry respecting the other voyages which the Portuguese had made to St George del Mina and the coast of Guinea, and he enjoyed great delight in discoursing with such as had sailed to those parts. I cannot certainly determine whether he ever went to Mina or Guinea during the life of this wife. But while he resided in Portugal he seriously reflected on the information he had thus received; and concluded, as the Portuguese had made discoveries so far to the southward, it was reasonable to conclude that land might be discovered by sailing to the westwards. To assist his judgment, he again went over the cosmographers which he had formerly studied, and considered maturely the astronomical reasons which corroborated this new opinion. He carefully weighed likewise the information and opinions on this subject of all with whom he conversed, particularly sailors. From an attentive consideration of all that occurred to him, he at length concluded that there must be many lands to the west of the Canary and Cape de Verd islands; and that it must be perfectly possible to sail to and discover them. But, that it may distinctly appear by what train of arguments he came to deduce so vast an undertaking, and that I may satisfy those who are curious to know the motives which induced him to encounter so great danger, and which led him to his great discovery, I shall now endeavour to relate what I have found among his own papers respecting this matter.

The motives which induced my father to undertake the discovery of the West Indies were three. Natural reason, authority of authors, and the testimony of sailors. From natural reason my father concluded that the whole sea and land of this world composed a globe or sphere, which might assuredly be gone round, so that men should stand with their feet directly against the feet of other men, in any precisely opposite parts whatever. Secondly, he took it for granted upon the authority of approved authors that a great portion of our globe had been already travelled over and explored; and that it now only remained to discover the whole, so as to make known what was contained in the vacant space which remained, between the eastern boundaries of India which were known to Ptolemy and Marinus, and those our newly discovered western parts of the coast of Africa and the Azores and Cape Verd islands, the most westerly which were yet known. Thirdly, he concluded that this still unknown space, between the eastern limits known to Marinus and the Cape Verds, could not exceed a third part of the circumference of the globe; since Marinus had already described 15 hours towards the east, out of the 24 parts or hours into which the circumference of the world is divided by the diurnal course of the sun; and therefore to return in an easterly direction to the Cape Verd islands from the limits discovered by Marinus, or to proceed westerly from these islands to meet the eastern limits of Marinus, required only to pass over about 8 parts in 24 of the circumference of the earth8.

He reckoned, fourthly, that as the cosmography of Marinus had given an account of fifteen hours or parts of the circumference of the globe eastwards, and had not yet attained to a knowledge of the eastern extremity of the land, it followed of course that this eastern extremity must be considerably beyond those known limits; and consequently, that the farther it extended eastwards, so much the nearer it must approach to the Cape Verd islands, or the then known western limits of the globe: And, if this space were sea, it might be easily sailed over in a short time; and if land, that it would be much sooner discovered by sailing to the west, since it must be much nearer to these islands in that direction. To this may be added what is related by Strabo in his Fifteenth Book, that no army ever penetrated to the eastern bounds of India, which according to Ctesias is as extensive as all the rest of Asia. Onesicritus affirms that India is a full third part of the world; and Nearchus says that it is four months journey in a straight line from west to east. Pliny, in the 17th Chap, of his 6th Book, says that India is a third part of the earth, and that consequently it must be nearer Spain in the western than in the eastern direction.

The fifth argument which induced the admiral to believe that the distance in a western direction to India was small, was taken from the opinion of Alfragranus and his followers, who computed the circumference of the globe as much less than all other cosmographical writers, as they only allowed 56-2/3 miles to a degree of longitude. Whence my father inferred, that the whole globe being small, the extent of that third part which remained to be discovered must necessarily be proportionally small likewise; and might therefore be sailed over in a short time. And, as the eastern bounds of India were not yet discovered, and must lie considerably nearer us towards the west, he therefore considered that the lands which he might discover in his proposed expedition westwards might properly be denominated the Indies. Hence it appears how much Roderick the archdeacon of Seville was wrong in blaming the admiral for calling those parts the Indies which were not so. But the admiral did not call them the Indies as having been seen or discovered by any other person; but as being in his opinion the eastern part of India beyond the Ganges, to which no cosmographer had ever assigned any precise limits, or made it to border upon any other country farther to the east, considering those unknown parts of eastern India to border on the ocean. And because he believed those countries which he expected to discover formed the eastern and formerly unknown lands of India, and had no appropriate name of their own, he therefore gave them the name of the nearest known country, and called them the West Indies. He was, so much the more induced to choose this appellation that the riches and wealth of India were well known, and he thereby expected the more readily to induce their Catholic Majesties to accede to his proposed undertaking, of the success of which they were doubtful; by saying that he intended to discover the way to India by the west: And he was desirous of being employed in the service of the crown of Castile, in preference to any other.

The second motive which encouraged the admiral to undertake his great enterprize, and which might reasonably induce him to call the countries he proposed to discover by the name of the Indies, was derived from the authority of learned men; who had affirmed that it was possible to sail from the western coast of Africa and Spain to the eastern bounds of India by the westwards, and that the sea which lay between these limits was of no great extent. This is affirmed by Aristotle, in his Second Book of the Heaven and of the World, as explained by Averroes; in which he says that a person may sail from India to Cadiz in a few days. Seneca, in his book of Nature, reflecting upon the knowledge of this world as insignificant in comparison with what shall be attained in a future life, says that a ship may sail in a few days with a fair wind from Spain to India. And if, as some suppose, the same Seneca were the author of the tragedies, he expresses himself to the same purpose in the following chorus of the Medea:

Venient annis Secula feris, quibus Oceanus Vincula rerum laxat, et ingens Pateat tellus, Typhysque novos Detegat orbes, nec sit terris Ultima Thule.

"There will come an age in latter times, when the ocean shall loosen the bonds of things, and a great country shall be discovered; when another Typhys shall find out new worlds, and Thule shall no longer remain the ultimate boundary of the earth."