One should never risk a joke, even of the mildest and most unexceptionable character, except among people of culture and wit. La Bruyère.

One should never think of death. One should think of life: that is real piety. Disraeli.

One should not lift the rod against our enemies upon the private information of another. Hitopadesa.

One should not neglect from time to time to renew friendly relations by personal intercourse. Goethe.

One shriek of hate would jar all the hymns of heaven: / True Devils with no ear, they howl in tune / With nothing but the Devil! Tennyson.

One sickly sheep infects the flock. Pr. 5

One sin opens the door to another. Pr.

One single moment is decisive both of man's life and his whole future. However he may reflect, each resolution he forms is but the work of a moment; the prudent alone seize the right one. Goethe.

One sinner destroyeth much good. Bible.

One solitary philosopher may be great, virtuous, and happy in the depth of poverty, but not a whole people. L. Iselin.