lier
treatise, and expressed the desire that for the future the "Essays"
might alone be regarded as containing his philosophical sentiments
and principles. In the "Essays" Hume brings to bear the results of
his criticism upon the problems of current speculative discussion.
The argument against miracles is still often discussed; and the
work is well worthy of the author whom many regard as the greatest
thinker of his time. In 1751 he published his "Inquiry Into the
Principles of Morals," which is one of the clearest expositions of
the leading principles of what is termed the utilitarian system.
Hume died on August 25, 1776.

_I.--Doubts Concerning the Understanding_

All the objects of human reason or inquiry may naturally be divided into
two kinds--to wit, _relations of ideas_ and _matters of fact_. Of the
first kind are the sciences of geometry, algebra, and arithmetic, and,
in short, every affirmation which is either intuitively or
demonstratively certain. "That the square of the hypotenuse is equal to
the squares of the two sides" is a proposition which expresses a
relation between these figures. "That three times five is equal to the
half of thirty" expresses a relation between these numbers.
Propositions of this kind are discoverable by the mere operation of
thought, without dependence on what is anywhere existent in the
universe. Though there never were a circle or triangle in nature, the
truths demonstrated by Euclid would for ever retain their certainty and
evidence.

Matters of fact, which are the second objects of human reason, are not
ascertained in the same manner; nor is our evidence of their truth,
however great, of a like nature with the foregoing. The contrary of
every matter of fact is still possible, because it can never imply a
contradiction, and is conceived by the mind with the same facility and
distinctness as if ever so conformable to reality. "That the sun will
not rise to-morrow" is no less intelligible a proposition, and implies
no more contradiction, than the affirmative that "it will rise." We
should in vain, therefore, attempt to demonstrate its falsehood. Were it
demonstratively false, it would imply a contradiction, and could never
be distinctly conceived by the mind.

It may, therefore, be a subject worthy of curiosity to inquire what is
the nature of that evidence which assures us of any real existence of
matters of fact beyond the