Thinking Is a Scarce Resource: How Feeling and Memory Select What We Think About

Deliberate thinking is limited in capacity, in time, and by the opportunity cost of every allocation, yet perception offers far more than reflection can address. This article asks how an encounter becomes worth that investment and when it ceases to be. Beginning from the experience of looking at scenery, it examines how memory, feeling, purposes, and salience shape what becomes an object of thought. Scarcity is defined by competing uses rather than depletion of a mental substance. Drawing on appraisal theory, research on emotional and value-driven attention, attentional engagement and disengagement, curiosity, and foraging models of search, the article argues that two forms of significance are routinely conflated: the significance that captures processing and the significance that warrants continued deliberation. A capture–investment–release framework separates entry into thought from its continuation and its ending. A marginal-value formulation defines warrant as the expected yield of further thought relative to its opportunity cost and specifies release, achieved through completion signals, plans, metacognitive reappraisal, or reallocation, as the point at which estimated yield falls below estimated opportunity cost. Crossing capture with warrant yields four patterns (warranted engagement, stale capture, neglected obligation, and appropriate passing), and failed release is explained as a persisting overestimate of yield. Feeling is treated as evidence about one's relation to an encounter, not as a measure of what deserves thought. Five directional propositions, each set against a rival account, specify how capture and investment should dissociate. Implications for the M⁵ model of mindfulness are outlined.