Dodds is describing a hydraulic psychology — the soul as a system of pressures held back by structures that cost something to maintain. The dykes are not neutral; they require continuous effort, and that effort is drawn from the same reservoir they contain. At some point the equation turns: more is held behind the wall than the wall was ever built to hold, and what breaks through is not gradual but sudden, total, civilizational in its scope. That word "civilisation" is doing real work here. It is not only the individual who collapses but the entire order of value the individual has organized a life around.

What Dodds is quietly tracking is the cost of the pneumatic preference — the wager that if you remain contained, elevated, in control, the elemental will eventually quiet down. It does not quiet down. It accumulates. The Dionysiac is not in itself the catastrophe; the catastrophe is the length and thoroughness of the resistance. Dionysus in the Bacchae is not malicious. He is simply patient. He waits for the moment when the held thing finds its own way out, bypassing every management strategy, arriving exactly where the work of containment was always meant to prevent. The break is not a punishment from outside. It is the return of what was never actually gone.