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 ...

REASON. 391
ims may be called principles of reasoning; for the words principles and elements are sometimes used as synonymous. Nor
do I take upon me to say that this mode of speaking is exceptionable. All that I assert is, that they cannot be called principles of reasoning, in the sense which has just now been defined;
and that accuracy requires, that the word, on which the whole
question hinges, should not be used in both senses, in the course
of the same argument. It is for this reason, that I have employed the phrase principles of reasoning on the one occasion,
and elements of reasoning on the other.
It is difficult to find unexceptionable language, to mark distinctions so completely foreign to the ordinary purposes of
speech; but, in the present instance, the line of separation is
strongly and clearly drawn by this criterion, - that fromi principles of reasoning, consequences may be deduced; from what I
have called elements of reasoning, none ever can.
A process of logical reasoning has often been likened to a
chain supporting a weight. If this similitude be adopted, the
axioms, or elemental truths now mentioned, may be compared
to the successive concatenations which connect the different
links immediately with each other; the principles of our reasoning resemble the hook, or rather the beam, from which the
whole is suspended.*, D'Alembert has defined the word principle exactly in the sense in
which I have used it; and has expressed himself (at least on one occasion) nearly as I have done, on the subject of axioms.
"What, then, are the truths which are entitled to have a place in the
elements of philosophy? They are of two kinds; those which form the
head of each part of the chain, and those which are to be found at the
points where different branches of the chain unite together.
" Truths of the first kind are distinguished by this, - that they do not
depend on any other truths, and that they possess within themselves the
whole grounds of their evidence. Some of my readers will be apt to
suppose, that I here mean to speak of axioms; but these are not the truths
which I have at present in view. With respect to this last class of principles, I must refer to what I have elsewhere said of them; that, notwithstanding their truth, they add nothing to our information; and that the
palpable evidence which accompanies them, amounts to nothing more