In partibus infidelium—In unbelieving countries.

In peace, there's nothing so becomes a man / As modest stillness and humility; / But when the blast of war blows in our ears, / Then imitate the action of the tiger; / Stiffen the sinews, summon up the blood, / Disguise fair Nature with hard-favour'd rage, / Then lend the eye a terrible aspect; / Let it pry through the portage of the head / Like the brass cannons. Hen. V., iii. 1.

In peace, who is not wise? Hitopadesa.

In perfect wedlock, the man, I should say, is the head, but the woman the heart, with which he cannot dispense. Rückert.

In perpetuam rei memoriam—In everlasting remembrance of a thing.

In pertusum ingerimus dicta dolium—We are pouring our words into a perforated cask, i.e., are throwing them away. Plaut.

In petto—Within the breast; in reserve. It.

In pios usus—For pious uses. 5

In Plato's opinion, man was made for philosophy; in Bacon's opinion, philosophy was made for man. Macaulay.

In pleno—In full.