vises, adapt our
methods of inquiry to THE NATURE OF THE IDEAS WE EXAMINE, and the truth
we search after. General and certain truths are only founded in the
habitudes and relations of ABSTRACT IDEAS. A sagacious and methodical
application of our thoughts, for the finding out these relations, is
the only way to discover all that can be put with truth and certainty
concerning them into general propositions. By what steps we are to
proceed in these, is to be learned in the schools of the mathematicians,
who, from very plain and easy beginnings, by gentle degrees, and
a continued chain of reasonings, proceed to the discovery and
demonstration of truths that appear at first sight beyond human
capacity. The art of finding proofs, and the admirable methods they have
invented for the singling out and laying in order those intermediate
ideas that demonstratively show the equality or inequality of
unapplicable quantities, is that which has carried them so far, and
produced such wonderful and unexpected discoveries: but whether
something like this, in respect of other ideas, as well as those of
magnitude, may not in time be found out, I will not determine. This,
I think, I may say, that if other ideas that are the real as well as
nominal essences of their species, were pursued in the way familiar to
mathematicians, they would carry our thoughts further, and with greater
evidence and clearness than possibly we are apt to imagine.

8. By which Morality also may be made clearer.

This gave me the confidence to advance that conjecture, which I suggest,
(chap. iii.) viz. that MORALITY is capable of demonstration as well as
mathematics. For the ideas that ethics are conversant about, being all
real essences, and such as I imagine have a discoverable connexion and
agreement one with another; so far as we can find their habitudes and
relations, so far we shall be possessed of certain, real, and general
truths; and I doubt not but, if a right method were taken, a great part
of morality might be made out with that clearness, that could leave, to
a considering man, no more reason to doubt, than he could have to
doubt of the truth of propositions in mathematics, which have been
demonstrated to him.

9. Our Knowledge of Substances is to be improved, not by contemplation
of abstract ideas, but only by Experience.

In our search after the knowledge of SUBSTANCES, our want of ideas that
are suitable to such a way of proceeding obliges us