A Treatise of Human Nature HTML version

It is evident, that all the sciences have a relation, greater or less, to human nature: and that
however wide any of them may seem to run from it, they still return back by one passage
or another. Even. Mathematics, Natural Philosophy, and Natural Religion, are in some
measure dependent on the science of MAN; since the lie under the cognizance of men,
and are judged of by their powers and faculties. It is impossible to tell what changes and
improvements we might make in these sciences were we thoroughly acquainted with the
extent and force of human understanding, and could explain the nature of the ideas we
employ, and of the operations we perform in our reasonings. And these improvements are
the more to be hoped for in natural religion, as it is not content with instructing us in the
nature of superior powers, but carries its views farther, to their disposition towards us,
and our duties towards them; and consequently we ourselves are not only the beings, that
reason, but also one of the objects, concerning which we reason.
If therefore the sciences of Mathematics, Natural Philosophy, and Natural Religion, have
such a dependence on the knowledge of man, what may be expected in the other sciences,
whose connexion with human nature is more close and intimate? The sole end of logic is
to explain the principles and operations of our reasoning faculty, and the nature of our
ideas: morals and criticism regard our tastes and sentiments: and politics consider men as
united in society, and dependent on each other. In these four sciences of Logic, Morals,
Criticism, and Politics, is comprehended almost everything, which it can any way import
us to be acquainted with, or which can tend either to the improvement or ornament of the
human mind.
Here then is the only expedient, from which we can hope for success in our philosophical
researches, to leave the tedious lingering method, which we have hitherto followed, and
instead of taking now and then a castle or village on the frontier, to march up directly to
the capital or center of these sciences, to human nature itself; which being once masters
of, we may every where else hope for an easy victory. From this station we may extend
our conquests over all those sciences, which more intimately concern human life, and
may afterwards proceed at leisure to discover more fully those, which are the objects of
pore curiosity. There is no question of importance, whose decision is not comprised in the
science of man; and there is none, which can be decided with any certainty, before we
become acquainted with that science. In pretending, therefore, to explain the principles of
human nature, we in effect propose a compleat system of the sciences, built on a
foundation almost entirely new, and the only one upon which they can stand with any
And as the science of man is the-only solid foundation for the other sciences, so the only
solid foundation we can give to this science itself must be laid on experience and
observation. It is no astonishing reflection to consider, that the application of
experimental philosophy to moral subjects should come after that to natural at the
distance of above a whole century; since we find in fact, that there was about the same
interval betwixt the origins of these sciences; and that reckoning from THALES to
SOCRATES, the space of time is nearly equal to that betwixt, my Lord Bacon and some
late philosophers [Mr. Locke, my Lord Shaftesbury, Dr. Mandeville, Mr. Hutchinson, Dr.
Butler, etc.] in England, who have begun to put the science of man on a new footing, and