"Each for each is what we teach"

"Each for each is what we teach" What is the source and meaning of this phrase?

My search for the source was useless, even though I dragged myself through one of the blogs on MySpace in a self-sacrificial effort to be thorough. If I'm not mistaken, the meaning is roughly the same as the motto of the Three Musketeers--All for one and one for all.

"Is what we teach." I've been looking for the source of the well-known chant,"Rooty-toot, rooty-toot,/ We're the boys from the Institute,/ We don't drink and we don't smoke/ And we don't tell a dirty joke." A little collegiate humor, you might say. Sophomoric at best.
SS