Carmen Sylva - Golden Thoughts of Carmen Sylva, Queen of Roumania (1900)
Archive.org direct link
Open Library main page
Writers through time have produced numerous books of sayings, often presented like this one as improving thoughts rather than witty aphorisms and often not improving anything, not even anybody's bank account. I'd never heard of this author but was surprised that the material has some substance and occasional bite. It sometimes leans towards bumper-sticker level (the introduction spends a lot of time trying to distinguish her from La Rochefoucauld) but overall is worth skimming.
Some samples:
Bad poets make of language what bad priests make of religion: a narrow prison.
When two women of intelligence can extract nothing from a man, be sure there is nothing in him.
Flatterers always begin by saying they cannot flatter.
There is a repulsive goodness as well as an attractive wickedness.
People call ugliness truth, just as they call coarseness candour.
A wife has to love you, suffer in childbirth, share your cares, direct your household, bring up your family, and be pretty and amiable into the bargain. What were you saying just now about her weakness?
Carmen Sylva was the pen name of Elisabeth of Wied (1843-1916), Queen of Romania from 1881-1914. She was a prolific writer, producing novels, plays, short stories, poetry, aphorisms, translations of Pierre Loti and folk songs. She seems to have written in French, English and German.