Note 1139 — AN ESSAY ON MAN, IN FOUR EPISTLES (continued 3)

Sir Isaac Newton showed the probability, converted into certainty by later observations, that comets travelled in elongated curves, and were subjected to the identical law of attraction which governed the motions of the planets. The laws of gravitation were the "rules" which "bound" the comets, and Pope contrasts these definite laws of matter with the variable "movements" of the human mind, which cannot be "fixed" or reduced to rule. The mind, however, has also its laws, which, notwithstanding the disturbing force of free-will, are sufficiently understood for the practical purposes of life.