In the James Stevenson cartoon, a professor in academic robes stands at the podium, ready to address the graduating class. He's a little heavy, a little shaggy, probably because he's too deep in professorial thought to take care of himself. He pauses, however, and confesses that his mind is so stuffed with information that he doesn't know where to begin.
It's true that any of us can struggle to find a useful thing to say. But the cartoon offers the odd non-context of graduation, where platitudes prevail. It's almost as if there is no meaningful context beyond the obvious there, and that's why so many graduation speeches restate the obvious. In a context-free space, the masses of information in the professor's head have nothing to attach to, and in spite of knowing everything he cannot speak. It is as though meaningful speech responds rather than initiates: it grows out of community, out of shared needs, out of previous speech that asks for a reply, out of problems we would like to address together. When we have a context, a shared problem, there is something for our thought to attach itself to. There is a place for our words to start and a reason in particular to start speaking. The cartoon catches the risk of the ivory tower, cut free from contexts that make speech matter, and there is the professor almost putting his finger on the problem but not actually getting close.
In my rough notes, I put it this way:
In the cartoon, the professor comes to the podium disheveled, and confesses that his brain is stuffed but he has no idea where to begin.
So there are the two kinds of knowledge: a systemizer with no context driving the discourse, and a person whose discourse is meant to respond to the world. The second has reasons to speak and contexts to use in inventing what to say. The first has information driven by its own abstraction, and no reason to speak or context to guide speech. In one, knowledge is prior to life or aside from it, and in the other knowledge is animated by life's demands.