The Underground Man believes that it is impossible for people to make decisions that are consistently in their best interest. Similarly, he believes that rationalism and free will are opposing concepts. This is a contradiction within rationalism that proposes that free will coincides with natural laws because people fundamentally strive for the good. In Chapter 9, he claims: “Good heavens, gentlemen, what sort of free will is left when we come to tabulation and arithmetic, when it will all be a case of twice two make four? Twice two makes four without my will. As if free will meant that!” (28). In other words, if free will corresponds with a set of predetermined laws, will ceases to be free. This is the central contradiction the Underground Man sees in the Socialists’ arguments for utopian society.

The Underground Man believes in scientific determinism, but not as the basis for human action. On the contrary, he posits that because humans are subject to a deterministic universe and have no control over experiences such as physical pain and mortality, the only way people can assert their humanity is through irrational actions. Reason accounts for only part of decision-making: