Reason

Reason names the best ways to use your mind: the methods that actually work, as opposed to whim, faith, hope, superstition, being led by emotion, or deferring to authority. CF treats reason as a skill you can study and develop, not a faculty everyone already possesses in adequate form. Most people’s notions of it are inherited secondhand from school and culture, and CF holds those notions to be both incomplete and seriously mistaken.

Reason has a purpose: to get good ideas, which splits into thinking of ideas and judging them. Because most possible ideas are errors, the harder and more important job is judging — a method for choosing among rival ideas. CF locates the core of that method in error correction: rational thinking uses criticism — explanations of mistakes — to find and fix errors, yielding open-ended progress rather than any final guarantee. This builds directly on Popper’s Critical Rationalism and its fallibilism, rejecting the justificationist demand to prove ideas true.

On CF’s account, a good idea solves a problem in a context, so you judge it by asking whether it does what it is for in the situation it will be used. An idea that hides its purpose or context cannot be evaluated and should be rejected — reason keeps high standards rather than accepting half-solutions. Crucially, irrationality is not feeling or intuition but blocking error correction; emotions and gut reactions are part of your mind and inputs to reasoning, not the opposite of it (reason vs emotion). Matching ambitions to abilities avoids the overreach that buries a life in unfixable mistakes.