Nouns ending in -esse are feminine.
The suffix often marks an abstract quality.
Is sagesse masculine or feminine?
lasagesse
The rule behind it
100% of -esse nouns are feminine
In context
« D'où vient cette superstition ? » « Appelons-la sagesse populaire. »
"Where's that superstition from?" "Call it folk wisdom."
La sagesse est un trésor pour l'éternité.
Wisdom is a treasure for eternity.
La solitude est l'école de la sagesse.
Solitude is the school of wisdom.