James begins this lecture by summarizing what we have learned so far: pragmatism, instead of adopting an attitude of “admiring contemplation” toward reality, “plunges forward into the river of experience” and judges all ideas on the basis of the “promise” they hold as to “this world’s outcome” (49). Typical of his popular style, James uses a physical metaphor to illustrate an abstract concept: Pragmatism helps us (fish) see that all our abstract ideas (air) must pass through and take into account concrete realities (water):

We are like fishes swimming in the sea of sense, bounded above by the superior element, but unable to breathe it pure or penetrate it […] We get our oxygen from it, however, we touch it incessantly […] and every time we touch it, we are reflected back into the water with our course re-determined and re-energized (49).

James applies the pragmatic method to another traditional philosophical concept: the problem of “the one and the many.” This deals with the question of whether reality is a unity or a plurality; whether the world consists of a single system or of many parts—and if many parts, how these might relate to one another.