Intuitionism is a philosophical approach to mathematics that emphasizes the role of mental constructions in understanding mathematical truths. It argues that mathematical objects are not discovered but created by the mind, and that mathematical statements are only true if they can be intuitively understood or constructed. In intuitionism, the focus is on the process of proving mathematical statements rather than on the statements themselves. This perspective challenges classical logic, particularly the law of excluded middle, which states that every proposition is either true or false. Key figures in this movement include L.E.J. Brouwer, who is considered its founder.