er the title of
_Essays on some Unsettled Questions of political Economy_, almost as
they now stand, except that in 1833 I partially rewrote the fifth Essay.
They were written with no immediate purpose of publication; and when,
some years later, I offered them to a publisher, he declined them. They
were only printed in 1844, after the success of the _System of Logic_. I
also resumed my speculations on this last subject, and puzzled myself,
like others before me, with the great paradox of the discovery of new
truths by general reasoning. As to the fact, there could be no doubt. As
little could it be doubted, that all reasoning is resolvable into
syllogisms, and that in every syllogism the conclusion is actually
contained and implied in the premises. How, being so contained and
implied, it could be new truth, and how the theorems of geometry, so
different in appearance from the definitions and axioms, could be all
contained in these, was a difficulty which no, one, I thought, had
sufficiently felt, and which, at all events, no one had succeeded in
clearing up. The explanations offered by Whately and others, though they
might give a temporary satisfaction, always, in my mind, left a mist
still hanging over the subject. At last, when reading a second or third
time the chapters on Reasoning in the second volume of Dugald Stewart,
interrogating myself on every point, and following out, as far as I knew
how, every topic of thought which the book suggested, I came upon an
idea of his respecting the use of axioms in ratiocination, which I did
not remember to have before noticed, but which now, in meditating on it,
seemed to me not only true of axioms, but of all general propositions
whatever, and to be the key of the whole perplexity. From this germ grew
the theory of the Syllogism propounded in the Second Book of the
_Logic_; which I immediately fixed by writing it out. And now, with
greatly increased hope of being able to produce a work on Logic, of some
originality and value, I proceeded to write the First Book, from the
rough and imperfect draft I had already made. What I now wrote became
the basis of that part of the subsequent Treatise; except that it did
not contain the Theory of Kinds, which was a later addition, suggested
by otherwise inextricable difficulties which met me in my first attempt
to work out the subject of some of the concluding chapters of the Third
Book. At the point which I had now reached I made a halt, w