Oxford English Dictionary: aphorism. Any principle, precept, or rule for behavior expressed in few words; a short pithy sentence containing a truth of general import; a maxim. ()
An original laconic phrase conveying some principle or concept of thought.
Wikipedia: aphorism. a concise, terse, laconic, and/or memorable expression of a general truth or principle. . . . often handed down by tradition from generation to generation
synonyms or variations: maxim, wise saying, epigram, apothegm, axiom, proverb, adage, moral, byword, motto, sound bite
Lord Acton: Power tends to corrupt, and absolute power corrupts absolutely.
http://www.dictionary.com/browse/aphorism: a terse saying embodying a general truth, or astute observation, as “Power tends to corrupt, and absolute power corrupts absolutely” (Lord Acton).
https://www.merriam-webster.com/dictionary/aphorism: a concise statement of a principle
https://en.wikipedia.org/wiki/Aphorism: Many societies have traditional sages or culture heroes to whom aphorisms are commonly attributed, such as the Seven Sages of Greece, Confucius or King Solomon.
[In American literature and culture: Mark Twain, Benjamin Franklin, Emerson, Dorothy Parker, Will Rogers . . . .]