François de la Rochefoucauld, Reflections; Or, Sentences and Moral Maxims (1665).
It is an odd sort of collection that takes as its object wisdom or advice. Yet it is indeed a long-standing one, indeed, that one can even find within most religious books.
La Rochefoucauld's collection, like most others, causes me to stumble, while reading; I find that my eyes glaze over after reading an aphorism or two, and I have trouble distinguishing one maxim from the next.
My conclusion remains that maxims are useful only in two cases: to inspire self-reflection, or to have a quotation to slip into something one is writing. Certainly, they are of no use in advance, and their wisdom is only really perceptible in retrospect.
An aphorism or four, for your amusement and your own collections:
If we resist our passions, it is oftener because they are weak than because we are strong.
True eloquence means saying all that is necessary and only what is necessary.
The pleasure of love lies in loving, and our own sensations make us happier than those we inspire.
We forgive to the extent that we love.
Most men, like plants, have hidden characteristics that chance brings to light.
When our integrity declines, our taste does also.
Those who have had great love affairs are forever glad, and forever sorry, that they have ended.
First Supplement, #VIII
If we cannot find peace inside ourselves, it is useless to look for it elsewhere.
Third Supplement, #XCII.
It is more necessary to study men than books.