One in their act to think and to pursue,
Sure to will right, and what they will to do.
Pope's meaning is, that there is no conflict in animals, as in man, between passion and reason, between desire and judgment, that there is not in the operations of animals, as in man's contrivances, a studied adaptation of means to ends, nor a balancing of method against method, and of end against end, but that animals are endowed with singleness of purpose, know instinctively what to do, and how to do it.
[1302] MS.:
Reason prefer to instinct if you can.
[1303] Addison, Spectator, No. 121; "To me instinct seems the immediate direction of Providence. A modern philosopher delivers the same opinion where he says, God himself is the soul of brutes." Upon the theory that brutes act from the immediate impulse of their Maker, there is a difficulty in explaining the cases of misdirected instinct, as when a jackdaw drops cart-loads of sticks down a chimney, in the vain endeavour to obtain a basis for its nest. Some animals, again, profit by experience, as foxes which improve in cunning, and we must infer that the assistance afforded by the Deity increases with the experience of the animals, though the experience is in nowise concerned in the result. A viciousness of temper, which resembles the evil passions of men, sometimes dominates in brutes, as we may see in horses and dogs, and we cannot ascribe these propensities to the immediate instigation of the Creator, unless we accept Pope's doctrine that God "pours fierce ambition into Cæsar's mind."
[1304] "Wood" in all editions, though designated as an erratum by Pope in his small edition of 1736. The mention of "tides" and "waves" in the next couplet should have called attention to a mistake, which seems obvious enough even without any special notice.—Croker.
[1305] This instinct is not invariable. Animals eat food poisoned artificially, and sometimes feed greedily upon poisonous natural products. Yew is a poison to cows and horses, and yet with an abundance of wholesome herbage they will sometimes eat the yew.
[1306] Every verb and epithet has here a descriptive force. We find more imagery from these lines to the end of the Epistle, than in any other parts of this Essay. The origin of the connections in social life, the account of the state of nature, the rise and effects of superstition and tyranny, and the restoration of true religion and just government, all these ought to be mentioned as passages that deserve high applause, nay, as some of the most exalted pieces of English poetry.—Warton.
[1307] The halcyon or king-fisher was reputed by the ancients "to build upon the wave," and the entrance to the floating nest was supposed to be contrived in a manner to admit the bird, and exclude the water of the sea. Either Pope believed the fable, or he thought himself at liberty to illustrate the marvels of instinct by fictitious examples. The couplet was originally thus in the MS.:
The cramp-fish, remora what secret charm
To stop the bark, arrest the distant arm?