The Will to Believe is a lecture by William James, which defends, in certain cases, the adoption of a belief without prior evidence of its truth. In particular, James is concerned in this lecture about defending the rationality of religious faith even lacking sufficient evidence of religious truth. In The Will to Believe, James suggests that what a person holds to be true or attainable may exist through that person’s belief in them, regardless of a lack of physical evidence. In a sense, he advocates the theory of self-fulfilling prophesies. The Will to Believe addresses several of the most important and perplexing problems of philosophy. In ten lucid essays William James deals with such subjects as causality and free will, the definition of the good life and the Good itself, the importance of the individual in society, and the intellectual claims of scientific method.