Nature, but to some vice of
human nature, which they therefore bewail, laugh at, mock, or, as is
more generally the case, detest; whilst he who knows how to revile most
eloquently or subtilely the weakness of the mind is looked upon as
divine.

It is true that very eminent men have not been wanting, to whose labor
and industry we confess ourselves much indebted, who have written many
excellent things about the right conduct of life, and who have given to
mortals counsels full of prudence. But no one so far as I know has
determined the nature and strength of the emotions, and what the mind is
able to do towards controlling them. I remember, indeed, that the
celebrated Descartes, although he believed that the mind is absolute
master over its own actions, tried nevertheless to explain by their
first causes human emotions, and at the same time to show the way by
which the mind could obtain absolute power over them. But in my opinion
he has shown nothing but the acuteness of his great intellect, as I
shall make evident in the proper place, for I wish to return to those
who prefer to detest and scoff at human affects and actions than
understand them.

To such as these it will doubtless seem a marvelous thing for me to
endeavor to treat by a geometrical method the vices and follies of men,
and to desire by a sure method to demonstrate those things which these
people cry out against as being opposed to reason, or as being vanities,
absurdities, and monstrosities. The following is my reason for so doing.
Nothing happens in Nature which can be attributed to any vice of Nature,
for she is always the same and everywhere one. Her virtue is the same,
and her power of acting; that is to say, her laws and rules, according
to which all things are and are changed from form to form, are
everywhere and always the same; so that there must also be one and the
same method of understanding the nature of all things whatsoever, that
is to say, by the universal laws and rules of Nature. The emotions,
therefore, of hatred, anger, envy, considered in themselves, follow from
the same necessity and virtue of Nature as other individual things; they
have therefore certain causes through which they are to be understood,
and certain properties which are just as worthy of being known as the
properties of any other thing in the contemplation alone of which we
delight. I shall, therefore, pursue the same method in considering the
nature and strength of th