It is characteristic of this series of philosophers that their attention was directed very largely upon the external world. It was natural that this should be so. Both in the history of the race and in that of the individual, we find that the attention is seized first by material things, and that it is long before a clear conception of the mind and of its knowledge is arrived at. Observation precedes reflection. When we come to think definitely about the mind, we are all apt to make use of notions which we have derived from our experience of external things. The very words we use to denote mental operations are in many instances taken from this outer realm. We "direct" the attention; we speak of "apprehension," of "conception," of "intuition." Our knowledge is "clear" or "obscure"; an oration is "brilliant"; an emotion is "sweet" or "bitter." What wonder that, as we read over the fragments that have come down to us from the Pre-Socratic philosophers, we should be struck by the fact that they sometimes leave out altogether and sometimes touch lightly upon a number of those things that we regard to-day as peculiarly within the province of the philosopher. They busied themselves with the world as they saw it, and certain things had hardly as yet come definitely within their horizon.
2. THE GREEK PHILOSOPHY AT ITS HEIGHT.—The next succeeding period sees certain classes of questions emerge into prominence which had attracted comparatively little attention from the men of an earlier day. Democritus of Abdera, to whom reference has been made above, belongs chronologically to this latter period, but his way of thinking makes us class him with the earlier philosophers. It was characteristic of these latter that they assumed rather naïvely that man can look upon the world and can know it, and can by thinking about it succeed in giving a reasonable account of it. That there may be a difference between the world as it really is and the world as it appears to man, and that it may be impossible for man to attain to a knowledge of the absolute truth of things, does not seem to have occurred to them.
The fifth century before Christ was, in Greece, a time of intense intellectual ferment. One is reminded, in reading of it, of the splendid years of the Renaissance in Italy, of the awakening of the human mind to a vigorous life which cast off the bonds of tradition and insisted upon the right of free and unfettered development. Athens was the center of this intellectual activity.
In this century arose the Sophists, public teachers who busied themselves with all departments of human knowledge, but seemed to lay no little emphasis upon certain questions that touched very nearly the life of man. Can man attain to truth at all—to a truth that is more than a mere truth to him, a seeming truth? Whence do the laws derive their authority? Is there such a thing as justice, as right? It was with such questions as these that the Sophists occupied themselves, and such questions as these have held the attention of mankind ever since. When they make their appearance in the life of a people or of an individual man, it means that there has been a rebirth, a birth into the life of reflection.
When Socrates, that greatest of teachers, felt called upon to refute the arguments of these men, he met them, so to speak, on their own ground, recognizing that the subjects of which they discoursed were, indeed, matter for scientific investigation. His attitude seemed to many conservative persons in his day a dangerous one; he was regarded as an innovator; he taught men to think and to raise questions where, before, the traditions of the fathers had seemed a sufficient guide to men's actions.
And, indeed, he could not do otherwise. Men had learned to reflect, and there had come into existence at least the beginnings of what we now sometimes rather loosely call the mental and moral sciences. In the works of Socrates' disciple Plato (428–347 B.C.) and in those of Plato's disciple Aristotle (384–322 B.C.), abundant justice is done to these fields of human activity. These two, the greatest among the Greek philosophers, differ from each other in many things, but it is worthy of remark that they both seem to regard the whole sphere of human knowledge as their province.
Plato is much more interested in the moral sciences than in the physical, but he, nevertheless, feels called upon to give an account of how the world was made and out of what sort of elements. He evidently does not take his own account very seriously, and recognizes that he is on uncertain ground. But he does not consider the matter beyond his jurisdiction.
As for Aristotle, that wonderful man seems to have found it possible to represent worthily every science known to his time, and to have marked out several new fields for his successors to cultivate. His philosophy covers physics, cosmology, zoölogy, logic, metaphysics, ethics, psychology, politics and economics, rhetoric and poetics.
Thus we see that the task of the philosopher was much the same at the period of the highest development of the Greek philosophy that it had been earlier. He was supposed to give an account of the system of things. But the notion of what it means to give an account of the system of things had necessarily undergone some change. The philosopher had to be something more than a natural philosopher.
3. PHILOSOPHY AS A GUIDE TO LIFE.—At the close of the fourth century before Christ there arose the schools of the Stoics, the Epicureans, and the Skeptics. In them we seem to find a somewhat new conception of philosophy—philosophy appears as chiefly a guide to life. The Stoic emphasizes the necessity of living "according to nature," and dwells upon the character of the wise man; the Epicurean furnishes certain selfish maxims for getting through life as pleasantly as possible; the Skeptic counsels apathy, an indifference to all things—blessed is he who expects nothing, for he shall not be disappointed.
And yet, when we examine more closely these systems, we find a conception of philosophy not really so very different from that which had obtained before. We do not find, it is true, that disinterested passion for the attainment of truth which is the glory of science. Man seems quite too much concerned with the problem of his own happiness or unhappiness; he has grown morbid. Nevertheless, the practical maxims which obtain in each of these systems are based upon a certain view of the system of things as a whole.
The Stoic tells us of what the world consists; what was the beginning and what will be the end of things; what is the relation of the system of things to God. He develops a physics and a logic as well as a system of ethics. The Epicurean informs us that the world originated in a rain of atoms through space; he examines into the foundations of human knowledge; and he proceeds to make himself comfortable in a world from which he has removed those disturbing elements, the gods. The Skeptic decides that there is no such thing as truth, before he enunciates the dogma that it is not worth while to worry about anything. The philosophy of each school includes a view of the system of things as a whole. The philosopher still regarded the universe of knowledge as his province.
4. PHILOSOPHY IN THE MIDDLE AGES.—I cannot do more than mention Neo-Platonism, that half Greek and half Oriental system of doctrine which arose in the third century after Christ, the first system of importance after the schools mentioned above. But I must not pass it by without pointing out that the Neo-Platonic philosopher undertook to give an account of the origin, development, and end of the whole system of things.
In the Middle Ages there gradually grew up rather a sharp distinction between those things that can be known through the unaided reason and those things that can only be known through a supernatural revelation. The term "philosophy" came to be synonymous with knowledge attained by the natural light of reason. This seems to imply some sort of a limitation to the task of the philosopher. Philosophy is not synonymous with all knowledge.
But we must not forget to take note of the fact that philosophy, even with this limitation, constitutes a pretty wide field. It covers both the physical and the moral sciences. Nor should we omit to notice that the scholastic philosopher was at the same time a theologian. Albert the Great and St. Thomas Aquinas, the famous scholastics of the thirteenth century, had to write a "Summa Theologiae," or system of theology, as well as to treat of the other departments of human knowledge.
Why were these men not overwhelmed with the task set them by the tradition of their time? It was because the task was not, after all, so great as a modern man might conceive it to be. Gil Blas, in Le Sage's famous romance, finds it possible to become a skilled physician in the twinkling of an eye, when Dr. Sangrado has imparted to him the secret that the remedy for all diseases is to be found in bleeding the patient and in making him drink copiously of hot water. When little is known about