Traditionally, epistemology was conceived as first philosophy, that is, as an autonomous and purely normative (a priori) discipline that lays down universal criteria of knowledge, truth, and justification. According to this influential tradition, knowledge is justified true belief, and a belief is justified if it is properly basic, that is, self-evident or evident to the senses, or if it is derived from such a belief, whether deductively, inductively, or abductively.

The rise of naturalized epistemology began in the 1950s and 1960s when logical positivists, such as Rudolf Carnap (1891–1970) and Hans Reichenbach (1891-1953), and critical rationalists, such as Karl Popper (1902–1994), still advocated the view that the theory of scientific knowledge should be purely normative, strictly confined to contexts of justification and to the logical aspects of scientific discovery. Referring to the work of Michael Polanyi (1891–1976), Norwood Russell Hanson (1924–1967), and Thomas Kuhn (1922–1996) in dislodging epistemology from its status as first philosophy, W. V. O. Quine (1908–2000) introduced the term epistemology naturalized. He suggested that the epistemological enterprise had better be conceived in terms of interplay between normative and empirical concerns. As the latter are relevant to the former this means that, on the one hand, epistemology now ought to make full use of the findings of biology, (cognitive) psychology, sociology, and linguistics when dealing with issues of perception, memory, reasoning, belief formation, knowledge acquisition, and the like. On the other hand, epistemology may go on dealing with the normative aspects of these issues whether in the guise of logical reconstruction or conceptual analysis, or both. Precisely how the balance between structure and genesis should be struck is a matter of ongoing dispute. All naturalizing epistemologists are empiricists, but some take epistemology as a branch of descriptive science (D. T. Campbell) while others uphold its normativity as part of a multidisciplinary endeavor (Alvin I. Goldman).

An early example of naturalized epistemology is the genetic epistemology of the French psychologist Jean Piaget (1896–1980), who in cooperation with logicians such as Evert Willem Beth (1908–1964) and Leo Apostel (1925–1995) did much to undermine the gap between structure and genesis of knowledge. Other examples are Polanyi's theory of tacit knowledge and Popper's evolutionary epistemology, though the latter's rationalist ideal of objective knowledge without a knowing subject appears to counter its naturalism. Further examples of sophisticated naturalist epistemologies are Goldman's epistemics, the Austrian biologist Franz M. Wuketits's evolutionary epistemology, and Alvin Plantinga's reformed epistemology.

In regard to science and religion, naturalizing religious epistemology would mean fully employing the resources of the natural sciences, including evolutionary biology, paleoanthropology, and sociobiology, in accounting for the experiential and cognitive aspects of religious life. This can be done in more or less radical ways—for example, as part of a radical naturalistic program in philosophy that has no place for transcendence, whether supernatural or not. Or, in an equally radical way it might be done as part of a theistic program with a naturalistic epistemology as a subsidiary. In a more modest way it might be done as part of an empirical theology that takes inner worldly experiences of transcendence seriously, whether in the life of modern human beings or in the traces left by the earliest human ancestors.

See also EPISTEMOLOGY; EVOLUTIONARY EPISTEMOLOGY

ANDY F. SANDERS