Traditional epistemology treats knowledge as justified true belief—a propositional attitude standing in particular relations to truth and evidence. We propose a radical reconceptualization: knowledge is not belief but structure. Specifically, knowledge consists of differentiated representational particles (epistemic granules) that constitute an organism's subjective world-model—its 'My World.' This framework reorients epistemology's four foundational questions: What is knowledge? (differentiated representation organized by biological needs); Where does knowledge come from? (dual sources: need-driven experience and rational processing); What can we know? (determined by My World maturity, from 10% in infancy to 95% in expertise); What are knowledge's limits? (bounded by need-relevance and representational granularity). Drawing on My World Theory (Author, in press-b), the Granularity Principle (Author, in press-a), and hierarchical cognition (Author, in press-c), we show how this reconceptualization addresses persistent puzzles in epistemology: the integration of experience and reason, the nature of expertise, the development of knowledge from infancy through adulthood, the relationship between individual and shared knowledge, and the response to skepticism. We engage extensively with empiricism (Locke, Hume), Kant's critical philosophy (adopting his insight about experience requiring conceptual structure while rejecting fixed a priori categories), pragmatism (James, Dewey), and embodied cognition (Varela, Thompson). The resulting epistemology is naturalistic yet normative, individualistic yet socially embedded, and provides novel frameworks for understanding scientific knowledge, pedagogical practice, and artificial intelligence.Clarification on maturity percentages: The percentages used in this paper (e.g., 10% epistemic development in infancy, approaching 95% in expertise) are indicative estimates of relative representational completeness, not precise empirical measurements. They represent the approximate proportion of domain-specific conceptual distinctions an individual has differentiated relative to a domain expert baseline, calibrated from developmental psychology and expertise research. The full My World Maturity Scale is detailed in My World (Author, in press-b) and Temporality (Author, in press).My World maturity percentages—methodological note: The percentages used here (e.g., 10% in infancy, 95% in expertise) are INDICATIVE ESTIMATES of relative representational completeness rather than precise empirical measurements. They represent the proportion of domain-specific conceptual distinctions that an individual has differentiated relative to a domain expert baseline. Operationalization: In principle, My World maturity in a domain D could be measured as (number of discriminable sub-categories an individual can reliably distinguish in D) / (number of discriminable sub-categories a domain expert can distinguish in D). This is analogous to expert-novice comparisons in cognitive psychology (Chase & Simon, 1973), which show novice chess players perceiving 'pieces on a board' while masters perceive structured 'pawn structures, piece coordination, king safety.' The maturity scale is introduced in the companion paper My World (Author, in press-b) and systematically developed in the companion paper Temporality (Author, in press). Its presence here is an application of that developmental framework to epistemological questions.
Heng Liu (Sat,) studied this question.