the Lamplighter

Homo qui erranti comiter monstrat viam, Quasi lumen de suo lumine accendit, facit: Nihilominus ipsi luceat, cum illi accenderit.

"He who kindly shows the way to one who has missed it, is as one who has lighted another's lamp from his own lamp; it none the less gives light to himself when it burns for the other."

~Quintus Ennius, quoted by Cicero in De Officiis.