"Unlike the physicist, the psychologist … investigates processes that belong to the same order—perception, learning, thinking—as those by which he conducts his investigation."

“In regard to the terrors as well as the superstitions and immoralities of religion, it will not do to urge that they are due only to the imperfections of the men who professed the various religions. If religion cannot restrain evil, it cannot claim effective power for good.”

“The realization of the pathetic frailty of the knowledge or beliefs on which our life depends thus leads not to despair but to open-eyed courage. But it also points to a most intimate connection between scientific method and liberal civilization. Science is not, as is popularly conceived, a new set of dogmas taught by a newer and better set of priests called scientists. It is rather a method which is based on a critical attitude to all plausible and self-evident propositions. It seeks not to reject them, but to find out what evidence there is to support them rather than their possible alternatives. This open eye for possible alternatives, each to receive the same logical treatment before we can determine which is the better grounded, is the essence of liberalism in art, morals, and politics. . . . Like science, liberalism insists on a critical examination of the content of all our beliefs, principles, or initial hypotheses and on subjecting them to a continuous process of verification so that they will be progressively better founded in experience and reason.”

“It has generally been assumed that of two opposing systems of philosophy, e. g., realism and idealism, one only can be true and one must be false; and so philosophers have been hopelessly divided on the question, which is the true one.”

“Liberalism, on the other hand, regards life as an adventure in which we must take risks in new situations, in which there is no guarantee that the new will always be the good or the true, in which progress is a precarious achievement rather than inevitability.”