All this is clear and simple. The confusion began when these two terms, instead of being coördinate, were subordinated to each other by the philosophers of Greece, so that what from one point of view was called a genus, might from another be called a species, and vice versâ. Human beings, for instance, were now called a species, all living beings a genus, which may be true in logic, but is utterly false in what is older than logic—viz., language, thought, or fact. According to language, according to reason, and according to nature, all human beings constitute a γένος, or generation, so long as they are supposed to have common ancestors; but with regard to all living beings we can only say that they form an εἶδος—that is, agree in certain appearances, until it has been proved that even Mr. Darwin was too modest in admitting at least four or five different ancestors for the whole animal world.[15]
In tracing the history of these two words, γένος and εἶδος, you may see passing before your eyes almost the whole panorama of philosophy, from Plato's "ideas" down to Hegel's Idee. The question of genera, their origin and subdivision, occupied chiefly the attention of natural philosophers, who, after long controversies about the origin and classification of genera and species, seem at last, thanks to the clear sight of Darwin, to have arrived at the old truth which was prefigured in language—namely, that Nature knows nothing [pg 036] but genera, or generations, to be traced back to a limited number of ancestors, and that the so-called species are only genera, whose genealogical descent is as yet more or less obscure.
But the question as to the nature of the εἶδος became a vital question in every system of philosophy. Granting, for instance, that women in every clime and country formed one species, it was soon asked what constituted a species? If all women shared a common form, what was that form? Where was it? So long as it was supposed that all women descended from Eve, the difficulty might be slurred over by the name of heredity. But the more thoughtful would ask even then how it was that, while all individual women came and went and vanished, the form in which they were cast remained the same?
Here you see how philosophical mythology springs up. The very question what εἶδος or species or form was, and where these things were kept, changed those words from predicates into subjects. εἶδος was conceived as something independent and substantial, something within or above the individuals participating in it, something unchangeable and eternal. Soon there arose as many εἴδη or forms or types as there were general concepts. They were considered the only true realities of which the phenomenal world is only as a shadow that soon passeth away. Here we have, in fact, the origin of Plato's ideas, and of the various systems of idealism which followed his lead, while the opposite opinion that ideas have no independent existence, and that the one is nowhere found except in the many (τὸ ἕν παρὰ τὰ πολλά), was strenuously defended by Aristotle and his followers.[16]
The same red thread runs through the whole philosophy of the Middle Ages. Men were cited before councils and condemned as heretics because they declared that animal, man, or woman were mere names, and that they could not bring themselves to believe in an ideal animal, an ideal man, an ideal woman as the invisible, supernatural, or metaphysical types of the ordinary animal, the individual man, the single woman. Those philosophers, called Nominalists, in opposition to the Realists, declared that all general terms were names only, and that nothing could claim reality but the individual.
We cannot follow this controversy farther, as it turns up again between Locke and Leibniz, between Herbart and Hegel. Suffice it to say that the knot, as it was tied by language, can be untied by the science of language alone, which teaches us that there is and can be no such thing as “a name only.” That phrase ought to be banished from all works on philosophy. A name is and always has been the subjective side of our knowledge, but that subjective side is as impossible without an objective side as a key is without a lock. It is useless to ask which of the two is the more real, for they are real only by being, not two, but one. Realism is as one-sided as Nominalism. But there is a higher Nominalism, which might better be called the Science of Language, and which teaches us that, apart from sensuous perception, all human knowledge is by names and by names only, and that the object of names is always the general.
This is but one out of hundreds and thousands of cases to show how names and concepts which come to us by tradition must be submitted to very careful snuffing before they will yield a pure light. What I [pg 038] mean by academic teaching and academic study is exactly this process of snuffing, this changing of traditional words into living words, this tracing of modern thought back to ancient primitive thought, this living, as it were, once more, so far as it concerns us, the whole history of human thought ourselves, till we are as little afraid to differ from Plato or Aristotle as from Comte or Darwin.
Plato and Aristotle are, no doubt, great names; every school-boy is awed by them, even though he may have read very little of their writings. This, too, is a kind of dogmatism that requires correction. Now, at his University, a young student might chance to hear the following, by no means respectful, remarks about Aristotle, which I copy from one of the greatest English scholars and philosophers: “There is nothing so absurd that the old philosophers, as Cicero saith, who was one of them, have not some of them maintained; and I believe that scarce anything can be more absurdly said in natural philosophy than that which now is called Aristotle's Metaphysics; or more repugnant to government than much of that he hath said in his Politics; nor more ignorantly than a great part of his Ethics.” I am far from approving this judgment, but I think that the shock which a young scholar receives on seeing his idols so mercilessly broken is salutary. It throws him back on his own resources; it makes him honest to himself. If he thinks the criticism thus passed on Aristotle unfair, he will begin to read his works with new eyes. He will not only construe his words, but try to reconstruct in his own mind the thoughts so carefully elaborated by that ancient philosopher. He will judge of their truth without being swayed by [pg 039] the authority of a great name, and probably in the end value what is valuable in Aristotle, or Plato, or any other great philosopher far more highly and honestly than if he had never seen them trodden under foot.
Do not suppose that I look upon the Universities as purely iconoclastic, as chiefly intended to teach us how to break the idols of the schools. Far from it! But I do look upon them as meant to supply a fresher atmosphere than we breathed at school, and to shake our mind to its very roots, as a storm shakes the young oaks, not to throw them down, but to make them grasp all the more firmly the hard soil of fact and truth! “Stand upright on thy feet” ought to be written over the gate of every college, if the epidemic of uniformity and sequacity which Mill saw approaching from China, and which since his time has made such rapid progress Westward, is ever to be stayed.
Academic freedom is not without its dangers; but there are dangers which it is safer to face than to avoid. In Germany—so far as my own experience goes—students are often left too much to themselves, and it is only the cleverest among them, or those who are personally recommended, who receive from the professors that individual guidance and encouragement which should and could be easily extended to all.