Jacomo Casanova (1725-1798) was a notorious Italian adventure seeker and writer, particularly known for his amourous exploits. Gallica has made Casanova's manuscripts available online. Namely, "Histoire de ma vie" ("History of my life"). Nothing extraordinary, of course, unless you intend to gain more knowledge about the man's personality studying his handwriting. It was interesting, however, to look into his use of Latin mottos and even a brief discussion of them in the book. For instance, this motto is used as an epigraph to the memoirs:
Nequiquam sapit qui sibi non sapit.
He knows in vain who does not draw profit from what he knows
Casonova ascribes this quote to Cicero. He must be quoting from his memory, because the exact quote is a bit different:
Qui ipse sibi sapiens prodesse non quit, nequiquam sapit.
Also, Cicero himself is quoting from Ennius's Medea.
In the book, Casanova also mentioned these two mottos:
Excitat auditor studium, laudataque virtus crescit, et immensum gloria calcar habet.
Having an audience makes one try harder, virtue grows by praise, and fame is a powerful spur
This one is from Ovid's "Epistulae ex Ponto." Another commonsense motto is also among Casanova's favorites, but he says that it would offend the vast number of thos who, whenever anything goes wrong for them, say: "It is not my fault":
Nemo leditur nisi a seipso
Nobody suffers except by his own doing