Now, I have no means of totally disproving such charges as this which the Judge makes. A man cannot prove a negative; but he has a right to claim, that when a man makes an affirmative charge, he must offer some proof to show the truth of what he says. I certainly cannot introduce testimony to show the negative about things, but I have a right to claim that if a man says he knows a thing, then he must show how he knows it. I always have a right to claim this, and it is not satisfactory to me that he may be “conscientious” on the subject.

Does the author use a consistent tone in the passage?