our knowledge of the human mind, and of the history of speculation; as the comparative anatomist's decisions are founded on his knowledge of the animal structure. Where so much is conjectural, much will necessarily be erroneous. How far we have erred, it is for readers to decide.

BOOK I.

THE PHYSIOLOGISTS.*

CHAPTER I.

THALES.

ALTHOUGH the events of his life, no less than the precise doctrines of his philosophy, are shrouded in mystery, and belong rather to the domain of fable, nevertheless Thales is very justly considered as the father of Greek Speculation. He made an epoch. He laid the first foundation stone of Greek philosophy. The step he took was small, but it was decisive. Accordingly, although nothing but a few of his tenets remain, and those tenets fragmentary and incoherent, we know enough of the general tendency of his doctrines, to speak of him with some degree of certitude.

Thales was born at Miletus, a Greek colony in Asia Minor. The date of his birth is extremely doubtful; but the first year of the 35th Olympiad is generally accepted as correct. He belonged to one of the most illustrious families of Phoenicia ; and took a conspicuous part in all the political

*We are forced, though unwillingly, to follow other historians in the use of the word physiology in its primitive sense. It has another and very different meaning in English, always signifying biology. But we have no other word wherewith to translate quoλoyo, or "inquirers into external

nature."

affairs of his country: a part which earned for him the highest esteem of his fellow citizens. His immense activity in politics has been denied, by later writers, as inconsistent with the tradition, countenanced by Plato, of his having spent a life of solitude and meditation ; while, on the other hand, his affection for solitude has been questioned on the ground of his political activity. It seems to us that the two things are perfectly compatible. Meditation does not necessarily unfit a man for action; nor does an active life absorb all his time, leaving him none for meditation. The wise man will strengthen himself by meditation, before he acts; and he will act, to test the truth of his opinions. Thales was one of the Seven Sages. This reputation is sufficient to settle the dispute. It shows that he could not have been a mere Speculative Thinker; for the Greek Sages were all moralists rather than metaphysicians. It shows also that he could not have been a mere man of action. His magnificent aphorism "know thyself" reveals the solitary meditative thinker.

Miletus was one of the most flourishing Greek colonies; and, at the period we are now speaking of, before either a Persian or a Lydian yoke had crushed the energies of its population, it was a fine scene for the development of mental energies. Its commerce both by sea and land was immense. Its political constitution afforded the finest opportunities for individual development. Thales both by birth and education would naturally have been fixed there; and would not, as it as often been said, have travelled into Egypt and Crete for the prosecution of his studies. These assertions, though frequently repeated, are based on no trusty authority. The only ground for the conjecture is the

fact of Thales being a proficient in mathematical knowledge; and from very early times, as we see in Herodotus, it was the fashion to derive the origin of almost every branch of knowledge from Egypt. So little consistency is there, however, in this narrative of his voyages, that he is said to have astonished the Egyptians, by showing them how to measure the height of their pyramids by their shadows. A nation so easily astonished by one of the simplest of mathematical problems could have had little to teach. Perhaps the strongest proof that he never travelled into Egypt-or that, if he travelled there, that he never came into communication with the priests-is the absence of all trace, however slight, of any Egyptian doctrine in the philosophy of Thales which he might not have found at home. To that philosophy we now address ourselves.

The distinctive characteristic of the Ionian School, in its first period, was that of physiological inquiry into the constitution of the universe. Thales opened this inquiry. It is commonly said, "Thales taught that the principle of all things was water." On a first glance, this will perhaps appear a mere extravagance. A smile of pity will greet it, accompanied by a reflection on the smiler's part, of the unlikelihood of his having ever believed in such an absurdity. But the serious student will be slow to accuse his predecessors of extravagance. The history of philosophy may be the history of errors; it is not that of follies. All the systems that have appeared have had a pregnant meaning. Only for this could they have been accepted. The meaning was proportionate to the opinions of the epoch, and as such is worth penetrating. Thales was one of the most extraordinary men that ever lived, and produced a most extra