Naturalized Epistemology is an approach to the theory of knowledge that seeks to replace or transform traditional epistemology by integrating it with the methods and findings of the empirical sciences, particularly psychology and cognitive science. It was most prominently developed by the American philosopher Willard Van Orman Quine in his influential essay *Epistemology Naturalized* (1969). Quine argued that the traditional project of epistemology, which aimed to justify knowledge through a priori philosophical analysis, had failed. Instead of asking how knowledge ought to be justified from an independent philosophical standpoint, he proposed that epistemology should become a branch of empirical science concerned with understanding how human beings actually acquire beliefs about the world. Traditional epistemology has long been concerned with questions such as: What is knowledge? How can beliefs be justified? What distinguishes knowledge from mere opinion? Philosophers from Plato to Descartes, Locke, Hume, Kant, and the logical positivists attempted to establish secure foundations for knowledge. Many of them sought certainty through rational principles, self-evident truths, or sense experience. Quine believed that these foundationalist attempts were unsuccessful because they relied upon assumptions that could not themselves be justified without circularity or infinite regress. One of the major conditions that led Quine to propose Naturalized Epistemology was the collapse of foundationalism. Foundationalism maintains that all knowledge rests upon basic beliefs that are self-evident, incorrigible, or directly given through experience. According to this view, these basic beliefs provide a secure foundation from which all other beliefs can be logically derived. However, philosophers increasingly recognized that no beliefs appear to possess absolute certainty. Even sensory experiences are subject to interpretation, error, and conceptual influence. Quine argued that there is no privileged foundation upon which all knowledge can securely rest. Another important condition was the failure of the analytic-synthetic distinction. Logical positivists had distinguished between analytic truths, which are true by virtue of meaning alone, and synthetic truths, which depend upon empirical facts. This distinction played a central role in explaining how certain knowledge could exist independently of experience. In his famous essay *Two Dogmas of Empiricism* (1951), Quine criticized this distinction by arguing that no clear criterion exists for separating analytic from synthetic statements. Every statement, including those of logic and mathematics, belongs to an interconnected web of belief and may be revised if sufficient empirical evidence requires it. Closely connected with this criticism was Quine's rejection of reductionism. Reductionism claimed that every meaningful statement could ultimately be translated into statements concerning immediate sensory experience. Logical positivists believed that scientific knowledge could be reconstructed upon a basis of observation sentences. Quine argued that such reduction is impossible because individual statements are never tested in isolation. Scientific theories are tested as interconnected systems. Experience confronts the entire network of beliefs rather than single propositions. This insight became known as confirmation holism. Confirmation holism became another major condition motivating Naturalized Epistemology. According to Quine, evidence does not verify or falsify isolated