The direct man (or the man of action) is often possessed by feelings of revenge and may carry out that revenge quickly and effectively. Such a man is, of course, stupid, but he does act whereas the man of acute consciousness can never carry out any revenge. Instead, like a mouse, he will retreat to his hole, or corner, where he relives the insult, intensifying it, questioning and doubting it until his convictions are totally warped. Wallowing in his self-humiliation, he remains isolated in his own spite until his death.
A stone wall is the only thing that will stop the direct man of action if he is bent on revenge, but the Underground Man resents the implications of the stone wall; to him, the wall represents mathematics and deductions of natural science. The Underground Man dislikes both the laws of science and the direct man's ready acceptance of them. The direct man, for example, accepts unquestioningly the "proof" that man is "descended from a monkey." The Underground Man recognizes that it is better "to understand it all, to recognize it all" but he refuses to be reconciled to conclusions. His rebellion is painful.
Proof of the idea that acute consciousness renders a man in-active is illustrated in this discussion of revenge. The direct person, the man of action, can revenge himself without any thought processes; he never considers the various implications concerning the act of revenge — he just accomplishes it. Thus, revenge can be performed only by the stupid person who in this society is the "normal" person. The man of acute consciousness, however, considers and weighs all the various aspects of revenge; then, after all the contemplation, it is too late, it is too impossible, and it is too absurd. The paradox is that the normal or direct man considers revenge his due when he is insulted; the man of acute consciousness sees revenge, upon deliberating about it, as an act of a savage. Yet, paradoxically, the Underground Man, for not committing revenge, is considered a savage by his audience. The paradox deepens when the Underground Man with his intense self-consciousness and finely-honed sensitivity realizes the futility of confessing to an unsympathetic audience composed of men of direct action (savages). In using the idea of revenge, Dostoevsky undoubtedly had Hamlet in mind, in that Hamlet was prevented from taking revenge by thinking too long about it and by considering all the variant alternatives.
Now we understand why the Underground Man can never become anything, not even an insect. The only experiences he can have are those which he creates in his own mind. For example, when he returns to his hole and relives an insult, he tortures himself with imaginary insults until they become authentic.
This section also introduces two images which the Underground Man will later use as thematic motifs in commenting upon the nature of a scientific world. In the "stone wall" and the "twice two makes four" images, the Underground Man says that nothing will stop the direct man unless he runs into a stone wall. The "stone wall" is equated with the "laws of nature, the deductions of natural science, mathematics." The Underground Man, however, refuses to accept as binding the various conclusions of science. In contrast, the direct man can accept the idea that we are descended from apes, but the man of acute consciousness rebels against such conclusions. As an individual, he reserves the right to ignore the idea that twice two makes four. This, however, forces him into inertia and boredom.