Numberless fallacies, as we are often truly told, have originated in a
confusion of the 'copula,' and the 'verb of existence.' Would not the
distinction which Plato by the mouth of Parmenides makes between 'One is
one' and 'One has being' have saved us from this and many similar
confusions? We see again that a long period in the history of philosophy
was a barren tract, not uncultivated, but unfruitful, because there was no
inquiry into the relation of language and thought, and the metaphysical
imagination was incapable of supplying the missing link between words and
things. The famous dispute between Nominalists and Realists would never
have been heard of, if, instead of transferring the Platonic Ideas into a
crude Latin phraseology, the spirit of Plato had been truly understood and
appreciated. Upon the term substance at least two celebrated theological
controversies appear to hinge, which would not have existed, or at least
not in their present form, if we had 'interrogated' the word substance, as
Plato has the notions of Unity and Being. These weeds of philosophy have
struck their roots deep into the soil, and are always tending to reappear,
sometimes in new-fangled forms; while similar words, such as development,
evolution, law, and the like, are constantly put in the place of facts,
even by writers who profess to base truth entirely upon fact. In an
unmetaphysical age there is probably more metaphysics in the common sense
(i.e. more a priori assumption) than in any other, because there is more
complete unconsciousness that we are resting on our own ideas, while we
please ourselves with the conviction that we are resting on facts. We do
not consider how much metaphysics are required to place us above
metaphysics, or how difficult it is to prevent the forms of expression
which are ready made for our use from outrunning actual observation and
experiment.

In the last century the educated world were astonished to find that the
whole fabric of their ideas was falling to pieces, because Hume amused