A couple of years later, he took a year off to join a scientific expedition to Brazil, led by Louis Agassiz.
There he developed his pragmatic epistemology, which considers the meaning of ideas and the truth of beliefs not abstractly, but in terms of the practical difference they can make in people’s lives.
He explored the implications of this theory in areas of religious belief, metaphysics, human freedom and moral values, and social philosophy. materialism, as well as a thorough analysis of a phenomenological understanding of the self and consciousness, a “forward-looking” conception of truth (based on validation and revisable experience), a thorough-going metaphysical pluralism, and a commitment to a full view of agency in connection with communal and social concerns.
His dread over the sense of life’s absolute insecurity pushed him to become a virtual invalid in his parents’ home. By the spring of 1870, when James was twenty-eight years old, he experienced a critical moment while reading a treatment of human freedom by the French neo-Kantian Charles Renouvier.
He discovered the solution to his problem in the voluntaristic act of will whereby he could commit himself to believing in his own freedom despite any lack of objective evidence.