Modern psychology has shown that reason is far less powerful than it was once thought to be. To the extent that it functions at all, it does so because we have discovered work-arounds for the flaws in the hardware that has been provided to us by evolution. This is the correct observation at the heart of the conservative critique of rationalism. And yet modern psychology has also shown that certain problems can be solved only by reason. While reason may not be perfect, we have no choice but to work with what we have. Civilization depends on it.