Elements of the philosophy of the human mind. By Dugald Stewart. Rev. and abridged, with critical and explanatory notes, for the use of colleges and schools. By Francis Bowen ...

INTROD UCTION. 9
supposed vibrations, or other changes, in the state of the brain;
or to explain Memory, by means of supposed impressions and
traces in the sensorium; we evidently blend a collection of important and well-ascertained truths, with principles which rest
wholly on conjecture.*
The Analogy of Maktter no Guide to the Phioilopzhy of M:find.
B- eside this inattention to the proper limits of philosophical
inquiry, other sources of error, from which the science of physics is entirely exempted, have contributed to retard the progress of the philosophy of mind. Of these, the most important
proceed from that disposition which is so natural to every person, at the commencement of his philosophical pursuits, to explain intellectual and moral phenomena by the analogy of the
material world.
I before took notice of those habits of inattention to the subjects of our consciousness, which take their rise in that period
of our lives when we are necessarily employed in acquiring a
knowledge of the properties and laws of matter. In consequence of this early familiarity with the phenomena of the material world, they appear to us less mysterious than those of
mind; and we are apt to think that we have advanced one step
in explaining the latter, when we can point out some analogybetween them and the former. It is owing to the same circumstance, that we have scarcely any appropriated language with
[" When I speak," says Crousaz, in his Art of Thinking, " of desire,
contentment, trouble, apprehension, doubt, certainty, of affirming, denying, approving, blaming, -I pronounce words the meaning of which I distinctly
understand; and yet I do not represent the things spoken of under any
image or corporeal form. While the intellect, however, is thus busy about
its own phenomena, the imagination is also at work in presenting its analogical theories; but so far from aiding us, it only misleads our steps and
retards our progress. Would you know what thought is? It is precisely
that which passes within you when you think. Stop but here, and you
are sufficiently informed. But the imagination, eager to proceed further,
would gratify our curiosity by comparing it to file, to vapor, or to other
active and subtile principles in the material world. And to what can all
this tend, but to divert our attention from what thought is, and to fix it
upon what it is not? "1