hey 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 they lie
under the cognizance of men, and are judged of by their powers and
qualities. 'Tis 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.... To me it seems evident that the essence of mind
being equally unknown to us with that of external bodies, it must
be equally impossible to form any notion of its powers and
qualities otherwise than from careful and exact experiments, and
the observation of those particular effects which result from its
different circumstances and situations. And though we must
endeavour to render all our principles as universal as possible, by
tracing up our experiments to the utmost, and explaining all
effects from the simplest and fewest causes, 'tis still certain we
cannot go beyond experience; and any hypothesis that pretends to
discover the ultimate original qualities of human nature, ought at
first to be rejected as presumptuous and chimerical....

"But if this impossibility of explaining ultimate principles should
be esteemed a defect in the science of man, I will venture to
affirm, that it is a defect common to it with all the sciences, and
all the arts, in which we can employ ourselves, whether they be
such as are cultivated in the schools of the philosophers, or
practised in the shops of the meanest artisans. None of them can go
beyond experience, or establish any principles which are not
founded on that authority. Moral philosophy has, indeed, this
peculiar disadvantage, which is not found in natural, that in
collecting its experiments, it cannot make them purposely, with
premeditation, and after such a manner as to satisfy itself
concerning every particular difficulty which may arise. When I am
at a loss to know the effects of one body upon another in any
situation, I need only put them in that situation, and observe what
results from it. But should I endeavour to clear up in the same
manner any[15] doubt in moral philosophy, by pl