Ver. 283. 'Twas then, the studious head, &c.] The poet hath now described the rise, perfection, and decay of civil policy and religion in the more early times. But the design had been imperfect, had he dropped his discourse here. There was, in after-ages, a recovery of these from their several corruptions. Accordingly, he hath chosen that happy era for the conclusion of his song. But as good and ill governments and religions succeed one another without ceasing, he now leaveth facts, and turneth his discourse, from ver. 282 to 295, to speak of a more lasting reform of mankind, in the invention of those philosophic principles, by whose observance a policy and a religion may be for ever kept from sinking into tyranny and superstition:
'Twas then, the studious head, or generous mind,
Follow'r of God, or friend of human kind,
Poet or patriot, rose but to restore
The faith and moral, nature gave before; &c.
The easy and just transition into this subject from the foregoing is admirable. In the foregoing he had described the effects of self-love; and now, with great art and high probability, he maketh men's observations on these effects the occasion of those discoveries which they have made of the true principles of policy and religion, described in the present paragraph; and this he evidently hinteth at in that fine transition:
'Twas then, the studious head, &c.
Ver. 295. Such is the world's great harmony, &c.] Having thus described the true principles of civil and ecclesiastical policy, he proceedeth, from ver. 294 to 303, to illustrate the harmony between the two policies, by the universal harmony of nature:
Such is the world's great harmony, that springs
From order, union, full consent of things.
Thus, as in the beginning of this epistle he supported the general principle of mutual love or association, by considerations drawn from the particular properties of matter, and the mutual dependence between vegetable and animal life, so, in the conclusion, he hath enforced the particular principles of civil and religious society, from that general harmony, which springs, in part, from those properties and dependencies.
Ver. 303. For forms of government let fools contest; &c.] But now the poet, having so much commended the invention and inventors of the philosophic principles of religion and government, lest an evil use should be made of this, by men's resting in theory and speculation, as they have been always apt to do in matters where practice makes their happiness, he cautions his reader, from ver. 302 to 311, against this error. The seasonableness of this reproof will appear evident enough to those who know that mad disputes about liberty and prerogative had once well nigh overturned our constitution; while others about mystery and church authority had almost destroyed the very spirit of our religion.
Ver. 311. Man, like the generous vine, &c.] Having thus largely considered man in his social capacity, the poet, in order to fix a momentous truth in the mind of his reader, concludes the Epistle in recapitulating the two principles which concur to the support of this part of his character, namely, self-love and social, and in showing that they are only two different motions of the appetite to good, by which the Author of Nature hath enabled man to find his own happiness in the happiness of the whole. This he illustrates with a thought as sublime as that general harmony which he describes:
On their own axis as the planets run,
Yet make at once their circle round the sun;
So two consistent motions act the soul;
And one regards itself, and one the whole.
Thus God and nature linked the general frame,
And bade self-love and social be the same.