“Every man is, no doubt, by nature, first and principally recommended to his own care; and as he is fitter to take care of himself than of any other person, it is fit and right that it should be so.”

Context: A man's first care should be to avoid the reproaches of his own heart; his next to escape the censures of the world: if the last interferes with the former, it ought to be entirely neglected; but otherwise there cannot be a greater satisfaction to an honest mind, than to see those approbations which it gives itself seconded by the applauses of the public: a man is more sure of his conduct, when the verdict which he passes upon his own behaviour is thus warranted and confirmed by the opinion of all that know him.

On "Sir Roger", in The Spectator No. 122 (20 July 1711).

1910s, Address to the Knights of Columbus (1915)
Context: We should meet this situation by on the one hand seeing that these immigrants get all their rights as American citizens, and on the other hand insisting that they live up to their duties as American citizens. Any discrimination against aliens is a wrong, for it tends to put the immigrant at a disadvantage and to cause him to feel bitterness and resentment during the very years when he should be preparing himself for American citizenship. If an immigrant is not fit to become a citizen, he should not be allowed to come here. If he is fit, he should be given all the rights to earn his own livelihood, and to better himself, that any man can have. Take such a matter as the illiteracy test; I entirely agree with those who feel that many very excellent possible citizens would be barred improperly by an illiteracy test. But why do you not admit aliens under a bond to learn to read and write within a certain time? It would then be a duty to see that they were given ample opportunity to learn to read and write and that they were deported if they failed to take advantage of the opportunity.

1747
Letters to His Son on the Art of Becoming a Man of the World and a Gentleman (1774)
Variant: I recommend you to take care of the minutes: for hours will take care of themselves.

Third Thesis
Idea for a Universal History from a Cosmopolitan Point of View (1784)

Self-Culture (1838)

Second Treatise of Government, Ch. IX, sec. 123
Two Treatises of Government (1689)

Remarks on the Republican platform (1860)

1850s, Speech at Chicago (1858)
Context: I believe each individual is naturally entitled to do as he pleases with himself and the fruit of his labor, so far as it in no wise interferes with any other man's rights, that each community, as a State, has a right to do exactly as it pleases with all the concerns within that State that interfere with the right of no other State, and that the general government, upon principle, has no right to interfere with anything other than that general class of things that does concern the whole.

Source: The Science of Rights 1796, P. 119