What fundamental principle explains why the perception of reality often holds more power than reality itself?

The fundamental principle explaining why the perception of reality often holds more power than reality itself is articulated by the Thomas Theorem, which states: "If men define situations as real, they are real in their consequences." This theorem signifies that individuals and groups act not necessarily based on an objective, empirical reality, but rather on their subjective interpretation, belief, or understanding of that reality. "Defining situations as real" refers to the cognitive process where people construct meaning from their experiences, influenced by their personal biases, social learning, cultural norms, and shared narratives. This subjective definition then dictates their responses, emotions, and behaviors. "Real in their consequences" means that these actions, driven by the perceived reality, produce tangible, verifiable outcomes in the objective world, effectively making the subjectively held belief functionally true through its effects. For instance, if a widespread perception exists that a specific financial institution is unstable (perceived reality), individuals may rush to withdraw their funds, regardless of the institution's actual financial health (objective reality). The collective action, motivated by this perception, can then *causethe institution to fail, thereby transforming the initial perception into an objective outcome. Similarly, the placebo effect demonstrates that a patient's belief in the efficacy of a treatment (perceived reality) can lead to measurable physiological improvements (real consequences), even if the treatment itself has no inherent medicinal properties (objective reality). The power of perception lies in its direct influence on human action, which in turn shapes the environment and creates new realities, often overriding or superseding the impact of objective facts that are not perceived or are perceived differently.