to find some rule, by which to judge of what is admirable in the capacities
of men, or fortunate in the application of their faculties, before we
venture to pass a judgment on this branch of their merits, or pretend to
measure the degree of respect they may claim by their different
attainments.

To receive the informations of sense, is perhaps the earliest function of
an animal combined with an intellectual nature; and one great
accomplishment of the living agent consists in the force and sensibility of
his animal organs. The pleasures or pains to which he is exposed from this
quarter, constitute to him an important difference between the objects
which are thus brought to his knowledge; and it concerns him to distinguish
well, before he commits himself to the direction of appetite. He must
scrutinize the objects of one sense, by the perceptions of another; examine
with the eye, before he ventures to touch; and employ every means of
observation, before he gratifies the appetites of thirst and of hunger. A
discernment acquired by experience, becomes a faculty of his mind; and the
inferences of thought are sometimes not to be distinguished from the
perceptions of sense.

The objects around us, beside their separate appearances, have their
relations to each other. They suggest, when compared, what would not occur
when they are considered apart; they have their effects, and mutual
influences; they exhibit, in like circumstances, similar operations, and
uniform consequences. When we have found and expressed the points in which
the uniformity of their operations consists, we have ascertained a physical
law. Many such laws, and even the most important, are known to the vulgar,
and occur upon the smallest degrees of reflection; but others are hid under
a seeming confusion, which ordinary talents cannot remove; and are
therefore the objects of study, long observation, and superior capacity.