The Set Structure of Concepts: A Methodological Turn from Synchronic Analysis to Diachronic Construction

Traditional concept analysis often presupposes that the world itself contains classifications, seeking objective and exhaustive distinguishing features. This ontological obsession leads to circular definitions when dealing with complex concepts such as life and mind. This paper proposes a turn from ontology to epistemology: concepts are not objective mappings of the world in itself, but rather information compression and structural classification adopted by humans under limited cognitive capacity. Every concept inherently corresponds to an object set O and a feature set F. The order of their occurrence is that the object set O precedes the feature set F; that is, the determining order is O → F. The essence of definition is to further compress information and thereby produce structural classification through the genus concept and features in genus. Defining concepts by concepts necessarily confronts three possible trajectories in its logical structure: infinite iteration, circular definition, or the choice of termination. Due to limited cognitive resources, infinite iteration is unfeasible; because definition demands clarity, circular definition is untenable. Therefore, the chain of definition can ultimately only terminate at "primordial concepts" that can no longer be formally defined. Given the intractability of complex conceptual networks at the synchronic level, this paper argues that the method must shift from "analysis" to "construction." For the continuity of construction, this paper divides concepts into two categories. The first category of concepts lacks a network structure and possesses synchronic reproducibility; they can be constructed through analytic reduction and reproduction at present. The second category of concepts forms a network structure around life, and the process through which the structure of their real-world objects evolves cannot be synchronically reproduced; therefore, they must turn to a diachronic path. Taking "life" itself as the primordial concept, and combining first-category concepts from the simple to the complex through life-history deduction, their evolutionary process is reenacted. This methodological turn provides a genetic reconstruction path for the clarification and precision of practical philosophy.