In "Concord River," the opening chapter, Thoreau describes the river, evokes the Native Americans whose lives were intertwined with it long before the advent of English settlers, associates the Concord with the great rivers of this continent and others, and suggests the metaphorical nature of actual rivers as routes to the exploration of the unexplored territory in "the interior of continents." He places the Concord within a universal context as a symbol of the flow of time and life toward the eternal. He represents weeds on the bottom and objects floating by as "fulfilling their fate," and indicates his openness to what the river might teach in his resolution to "float whither it would bear me."
The brothers' journey begins in "Saturday." They depart from Concord, "a port of entry and departure for the bodies as well as the souls of men." On their first day, they travel as far as Billerica, Massachusetts. Thoreau describes what they see along the way, places the particular examples of humanity that they encounter within the all-encompassing scope of universal history, and likens life itself to a river, and the inevitable progress of a single life toward its absorption into infinity to the river's flow. The chapter contains a lengthy and detailed catalog of fishes. Despite the fragility and expendability of individual fishes, the race endures through the far-flung dissemination of its seeds. The lives of countless fishes are wasted as a matter of course, but there is a kind of virtue in their instinctive willingness to fulfill the role that nature has assigned them. The place where the brothers camp at night is described in classically sylvan terms. Past and present are intermingled throughout the chapter, and the specific employed to reveal universal significance. "Saturday" concludes with a discussion of night sounds, described as evidence of nature's health.
