'The law is an ass â€" an idiot … a __.'

A bachelor. Mr. Bumble had just been told that "the law supposes that your wife acts under your direction" (after blaming her for something that he himself was accused of doing). He responds, having made sure that his wife has left the room:

If the law supposes that, the law is an ass—an idiot. If that's the eye of the law, the law's a bachelor; and the worst I wish the law is, that his eye may be opened by experience—by experience.

UPDATE: I had originally heard this phrase as "the law is a ass," and most editions of Oliver Twist (including 1800s ones) use that phrase; but some—including some 1800s ones, such as the one I cited—use "the law is an ass," and I thought this would be less distracting. But it looks like it's distracting either way, since three readers e-mailed me to say it should have been "a ass." So I thought I'd flag this, for the benefit of readers who are interested in such things.