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 ...

iaIEMORY. 301
The advantages, however, we derive from true philosophy,
are incomparably greater than what are to be expected from
any hypothetical theories. These, indeed, may assist us in
recollecting the particulars we are already acquainted with;
but it is only from the laws of nature, which have been traced
analytically firom facts, that we can venture, with safety, to deduce consequences by reasoning'i priori. An example will
illustrate and confirm this observation.
Suppose that a glass tube, thirty inches long, is filled with
ceed one another in such a way as shall give us the greatest command over
our knowledge already acquired, and lead most directly to the acquisition
of more. The general problem of Classification, in reference to these purposes, may be stated as follows: To provide that things shall be thought of
in such groups, and those groups in such an order, as will best conduce to
the remembrance and to the ascertainment of their laws."
" There is no property of objects which may not be taken, if we please,
as the foundation for a classification or mental grouping of those objects;
and, in our first attempts, we are likely to select for that purpose properties
which are simple, easily conceived, and perceptible on a first view, without any previous process of thought. Thus, Tournefort's arrangement of
plants was founded on the shape and divisions of the corolla; and that
which is commonly called the Linnmean, (though Linnlmus also suggested
another and more scientific arrange~ment,) was grounded chiefly upon the
number of the stamens and pistils.
"But these classifications, which are at first recommended by the facility
theyafford us of ascertaining to what class any individual belongs, are
seldom much adapted to the ends of that Classification which is the subject
of our present remarks. [They are like the alphabetical arrangement of
words in a dictionary, which answers no other purpose than that of enabling us easily to find the particular word which we are in search of.]
The Linnman arrangement answers the purpose of making us think together of all those kinds of plants which possess the same number of staiens and pistils; but to think of them in that manner is of little use,
since we seldom have any thing to affirm in common of the plants which
have a given number of stamens and pistils.... And inasmuch as,
by habitually thinking of plants in these groups, we are prevented fiom
habitually thinking of them in groups which have a greater number of
properties in common, the effect of such a classification, when systematically adhered to, upon our habits of thought, must be regarded as mischievous.
"The ends of scientific classification are best answered when the objects
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