These illustrations seem sufficient to show a mental attitude towards facts which is certainly like that one has towards a far-off country which one does not expect to visit. The illustration I have used is curiously borne out by a passage in Lactantius, writing so far down as the fourth century, in which we have a picture of mediæval relations towards nature and of customary discussions.

"To search," says he, "for the causes of natural things; to inquire whether the sun be as large as he seems, whether the moon is convex or concave, whether the stars are fixed in the sky or float freely in the air; of what size and what material are the heavens; whether they be at rest or in motion; what is the magnitude of the earth; on what foundations it is suspended and balanced;—to dispute and conjecture on such matters is just as if we chose to discuss what we think of a city in a remote country of which we never heard but the name."

Perhaps this defect of thought, this lack of personality towards facts, is most strikingly perceived in the slowness with which most primary ideas of the form and motion of the earth made their way among men. Although astronomy is the oldest of sciences, and the only one progressive science of antiquity; and although the idea that the earth was a sphere, was one of the earliest in Greek philosophy; yet this same Lactantius in the 4th century is vehemently arguing as follows: "Is it possible that men can be so absurd as to believe that the crops and trees on the other side of the earth hang downwards, and that men there have their feet higher than their heads? If you ask of them how they defend these monstrosities—how things do not fall away from the earth on that side? they reply that the nature of things is such that heavy bodies tend towards the centre, like the spokes of a wheel, while light bodies, as clouds, smoke, fire, tend from the earth towards the heavens on all sides. Now I am really at a loss what to say of those who, when they have once gone wrong, steadily persevere in their folly and defend one absurd opinion by another."

And coming on down to the eighth century, the anecdote is well known of honest Bishop Virgil of Salisbury, who shocked some of his contemporaries by his belief in the real existence of the antipodes, to such an extent that many thought he should be censured by the Pope for an opinion which involved the existence of a whole "world of human beings out of reach of the conditions of salvation."

And finally we all know the tribulations of Columbus on this point far down in the fifteenth century, at the very beginning of the Renaissance.

Now this infirmity of mind is as I said, not distinctive of the Greek. To me it seems simply a natural incident of the youth of reason, of the childhood of personality. At any rate, for a dozen centuries and more after Aristotle's death, to study science, means to study Aristotle; in vain do we hear Roger Bacon in the thirteenth century—that prophet philosopher who first announces the two rallying cries of modern science, mathematics and experiment—in vain do we hear Roger Bacon crying: "If I had power over the works of Aristotle I would have them all burnt; for it is only a loss of time, a course of error, and a multiplication of ignorance beyond expression, to study them."

Various attempts have been made to account for the complete failure of Greek physical science by assigning this and that specific tendency to the Greek mind: but it seems a perfect confirmation of the view I have here presented—to wit that the organic error was not Greek but simply a part of the general human lack of personality—to reflect that 1,500 years after Aristotle, things are little better, and that when we do come to a time when physical science begins to be pursued upon progressive principles, we find it to be also a time when all other departments of activity begin to be similarly pursued, so that we are obliged to recognize not the correction of any specific error in Greek ratiocination, but a general advance of the spirit of man along the whole line.

And perhaps we have now sufficiently prepared ourselves, as was proposed at the outset of this sketch of Greek science, to measure precisely the height of the new plane which begins with Copernicus, Kepler and Galileo in the 16th century, over the old plane which ended with Aristotle and his commentators. Perhaps the true point up to which we should lay our line in making this measurement is not to be found until we pass nearly through the 17th century and arrive fairly at Sir Isaac Newton. For while each one of the great men who preceded him had made his contribution weighty enough, as such, yet each brings with him some old darkness out of the antique period.

When we come to examine Copernicus, we find that though the root of the matter is there, a palpable environment of the old cycle and epicycle still hampers it; Galileo disappoints us at various emergencies. Kepler puts forth his sublime laws amid a cluster of startling absurdities; Francis Bacon is on the whole unfaithful; Descartes will have his vortices or eddies as the true principles of motion of the heavenly bodies; and so it is not until we reach Sir Isaac Newton at the end of the 17th century that we find a large, quiet, wholesome thinker, de-Aristotleized, de-Ptolemized, de-Cartesianized, pacing forth upon the domain of reason as if it were his own orchard, and seating himself in the centre of the universe as if it were his own easy chair, observing the fact and inferring the law as if with a personal passion for truth and a personal religion towards order. In short, and in terms of our present theory, with Sir Isaac Newton the growth of man's personality has reached a point when it has developed a true personal relation between man and nature.

I should have been glad if the scope of this part of my inquiry had allowed me to give some sketch at least of the special workers in science who immediately preceded Newton, and some of whose lives were most pathetic and beautiful illustrations of this personal love for nature which I have tried to show as now coming into being for the first time in the history of man. Besides such spectacles as the lonesome researches of Jeremiah Horrox, for example, I scarcely know anything in history which yields such odd and instructive contrasts as those glimpses of the scientific work which went on about the court of Charles II, and of what seems to have been the genuine interest of the monarch himself. In Pepys' Diary, for instance, under date of May 11th, 1663, I find the entry: "Went home after a little discourse with Mr. Pierce the surgeon who tells me that ... the other day Dr. Clarke and he did dissect two bodies, a man and a woman, before the king, with which the king was highly pleased." Again, February 1st, of the next year: "Thence to Whitehall, where in the Duke's chamber the King came and stayed an hour or two, laughing at Sir W. Petty ... and at Gresham College in general: Gresham College he mightily laughed at for spending time only in weighing of air and doing nothing else since they sat." On the 4th, he was at St. Paul's school and "Dr. Wilkins" is one of the "posers," Dr. Wilkins being John Wilkins, Bishop of Chester, whose name was well-known in mathematics and in physics. Under date of March 1st, same year, the entry is: "To Gresham College where Mr. Hooke read a second very curious lecture about the late comet; among other things proving very probably that this is the very same comet that appeared before in the year 1618, and that in such a time probably it will appear again, which is a very new opinion; but all will be in print." And again on the 8th of August, 1666, I find an entry which is of considerable interest: "Discoursed with Mr. Hooke about the nature of sounds, and he did make me understand the nature of musical sounds made by strings mighty prettily; and told me that having come to a certain number of vibrations proper to make any tone, he is able to tell how many strokes a fly makes with her wings (those flies that hum in their flying) by the note that it answers to in music during their flying. That I suppose is a little too much refined; but his discourse in general of sound was mighty fine."