To furnish the most unremitted excitements of this kind, and
to urge man to further the gracious designs of Providence by the
full cultivation of the earth, it has been ordained that
population should increase much faster than food. This general
law (as it has appeared in the former parts of this Essay)
undoubtedly produces much partial evil, but a little reflection
may, perhaps, satisfy us, that it produces a great overbalance of
good. Strong excitements seem necessary to create exertion, and
to direct this exertion, and form the reasoning faculty, it seems
absolutely necessary, that the Supreme Being should act always
according to general laws. The constancy of the laws of nature,
or the certainty with which we may expect the same effects from
the same causes, is the foundation of the faculty of reason. If
in the ordinary course of things, the finger of God were
frequently visible, or to speak more correctly, if God were
frequently to change his purpose (for the finger of God is,
indeed, visible in every blade of grass that we see), a general
and fatal torpor of the human faculties would probably ensue;
even the bodily wants of mankind would cease to stimulate them to
exertion, could they not reasonably expect that if their efforts
were well directed they would be crowned with success. The
constancy of the laws of nature is the foundation of the industry
and foresight of the husbandman, the indefatigable ingenuity of
the artificer, the skilful researches of the physician and
anatomist, and the watchful observation and patient investigation
of the natural philosopher. To this constancy we owe all the
greatest and noblest efforts of intellect. To this constancy we
owe the immortal mind of a Newton.

As the reasons, therefore, for the constancy of the laws of