If it was necessary to pick one passage in the novel that exemplifies Crick's staggeringly dark and morose view of mankind and its struggle with history, this is the one:
And did I not bid you remember, children, that for each protagonist who once stepped onto the stage of so-called historical events, there were thousands, millions, who never entered the theatre - who never knew that the show was running - who got on with the donkey work of coping with reality?
True, true. But it doesn't stop there. Because each one of those numberless non-participants was doubtless concerned with raising in the flatness of his own unsung existence his own personal stage, his own props and scenery - for there are very few of us who can be, for any length of time, merely realistic. So there's no escaping it: even if we miss the grand repetoire of history, we yet imitate it in miniature, and endorse, in miniature, its longing for presence, for feature, for purpose, for content.
And there's no saying what consequences we won't risk, what reactions to our actions, what repurcussions, what brick towers built to be knocked down, what chasing of our own tails, what chaos we won't assent to in order to assure ourselves that, nonetheless, things are happening. And there's no saying what heady potions we won't concoct, what meanings, myths, manias we won't imbibe in order to convince ourselves that reality is not an empty vessel. (pp. 34-35)
His lecture, presumably one of the earlier ones in the school year, definitely sets the tone for what is to come. Tom Crick shows elements of desperation and despair throughout the passage.
He refers to individuals in society as "numberless non-participants", immediately stripping away any sense his students have that they might one day grow up to be special, to make a difference. Crick goes on to tell of "the flatness of [their] own unsung existence". There is little hope, in this History teacher's opinion, of achieving anything more out of life than struggling furiously to maintain the status quo.
The last lines in the passage express Crick's catch-22 view of life. There is a constant struggle, he believes, to prove that "reality is not an empty vessel", but the only way he seems to think mankind proves this is by concocting "heady potions" and chasing its own tail. Waterland is not a hope-filled book; its plot plods methodically on toward deeper and deeper despair. This early passage from Ch. 6 can perhaps be treated like a warning of exactly that.