Primary motivation is established in basic needs of unlearned behavior as humans try to survive. Hunger, thirst, and the avoidance of pain can all be considered primary motivators. In "That Morning," the speaker of the poem is called to this scene to fish for salmon, presumably in order to fulfill their hunger needs. Even if they are not hungry in that moment, the desire to avoid being hungry and this plan to capture food for another meal is based in the human quest for survival. Fishing for salmon can provide food to spare the speaker the pangs of hunger at some point.
Secondary motivation goes beyond basic survival and encompasses a sense of fulfillment, power, or achievement, which differs among individuals based on their own intrinsic values. In this poem, the speaker clearly has a deep appreciation of nature and the opportunity to surround themselves with these majestic salmon, a rushing river, and golden bears that awaken their soul, making them feel that they stand in the "light." This sense of fulfillment is captured in both the language and the tone as the speaker absorbs the natural world around him. The formations of the salmon as they move make the speaker feel a "blessing" that is so pure, and they are afraid that "one wrong thought might darken" the moment. The bears are described as both playful and majestic, taking a moment to rest as if they are "on a throne" in this river.
Both the primary and secondary motives are brought to closure in the final lines, as the speaker feels that they have been brought fully into the "light" through his experience of living for a moment in the world of such majestic creatures.