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 ...

THE INFLUENCE OF CASUAL ASSOCIATIONS. 253
"The Philosophy of Mindcl. has its alchemists also:- men
whose studies are directed to the pursuit of one single principle,
into which the whole science may be resolved, and who flatter
themselves -with the hope of discovering the grand secret, by
which the pure Gold of Truth may be produced at pleasure."
Among these alchemists in the science of the mind, the first
place is undoubtedly due to Dr. Hartley, who not only attempts
to account for all the phenomlena of human nature fiom the
single principle of association, combined with the h.ypothetical
assumption of an invisible fluid or ether, producing vibrations in
the medullary substance of the brain and nerves; but indulges
his imaoination in anticipating an era, i" when future generations
shall put all kinds of evidences and inquiries into mathematical
forms; reducing Aristotle's ten Categories and Bishop Wilkins'
forty Summa Genera, to the head of quantity alone, so as to
make Mathematics and Logic, Natural History and Civil History, Natural Philosophy and philosophy of all other kinds,
coincide omni ex parte." If I had never read another sentence
of this author, I should have required no further evidence of
the unsoundness of his understanding.
The nomenclature of philosophy. - I have only to add, that,
although I have retained the phrase of the association of ideas,
in compliance with common language, I am far from being completely satisfied with this mode of expression. I have retained
it, chiefly that I might not expose myself to the censure of
delivering old doctrines in a new form.
As I have endeavored to employ it with caution, I hope that it
has not often misled me in my reasonings. At the same time,
I am more and more convinced of the advantages to be derived
from a reformation of the common language, in most of the
branches of science. How much such a reformation has effected
in Chemistry is well known; and it is evidently much more
necessary in the Philosophy of Minc, where the prevailing language adds to the common inaccuracies of popular expressions,
the peculiar disadvantage of being all suggested by the analogy
of matter. Often, in the composition of this work, have I recollected the advice of Bergman to Morveau: " Ir reforming the
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