true meaning of these
words. At school, of course, all we can do is to teach the received
meaning of _genus_ and _species_; and if a boy can trace these terms back
to Aristotle's {~GREEK SMALL LETTER GAMMA~}{~GREEK SMALL LETTER EPSILON WITH OXIA~}{~GREEK SMALL LETTER NU~}{~GREEK SMALL LETTER OMICRON~}{~GREEK SMALL LETTER FINAL SIGMA~} and {~GREEK SMALL LETTER EPSILON~}{~GREEK SMALL LETTER IOTA WITH PSILI AND PERISPOMENI~}{~GREEK SMALL LETTER DELTA~}{~GREEK SMALL LETTER OMICRON~}{~GREEK SMALL LETTER FINAL SIGMA~}, and show in what sense that philosopher
used them, every examiner would be satisfied.

But the time comes when we have to act as our own examiners, and when we
have to give an account to ourselves of such words as _genus_ and
_species_. Some people write, indeed, as if they had seen a _species_ and
a _genus_ walking about in broad daylight; but a little consideration will
show us that these words express subjective concepts, and that, if the
whole world were silent, there would never have been a thought of a
_genus_ or a _species_. There are languages in which we look in vain for
corresponding words; and if we had been born in the atmosphere of such a
language, these terms and thoughts would not exist for us. They came to
us, directly or indirectly, from Aristotle. But Aristotle did not invent
them, he only defined them in his own way, so that, for instance,
according to him, all living beings would constitute a _genus_, men a
_species_, and Sokrates an _individual_.

No one would say that Aristotle had not a perfect right to define these
terms, if those who use them in his sense would only always remember that
they are thinking the thoughts of Aristotle, and not their own. The true
way to shake off the fetters of old words, and to learn to think our own
thoughts, is to follow them up from century to century, to watch their
development, and in the end to bring ourselves face to face with those who
first found and framed both words and thoughts. If we do this with _genus_
and _species_, we shall find that the words which Aristotle defined--viz.,
{~GREEK SMALL LETTER GAMMA~}{~GREEK SMALL LETTER EPSILON WITH OXIA~}{~GREEK SMALL LETTER NU~}{~GREEK SMALL LETTER OMICRON~}{~GREEK SMALL LETTER FINAL SIGMA~} and {~GREEK SMALL LETTER EPSILON~}{~GREEK SMALL LETTER IOTA WITH PSILI AND PERISPOMENI~}{~GREEK SMALL LETTER DELTA~}{~GREEK SMALL LETTER OMICRON~}{~GREEK SMALL LETTER FINAL SIGMA~}--had originally a very different and far mo