The branch of philosophy, first formally established at the University of London at the turn of the 20th-century, concerning itself with the critical examination of the methods and theories of the sciences. While a relatively 'new' field, the relationship between science and philosophy has figured prominently and problematically since at least the late-19th century with the post-Kantian non-dialectical materialists and critico-empiricists (Lange, Mach, Avenarius) and their conscious modelling of philosophy upon the phenomenalist principles of science. Since then, the sucessful momentum of the sciences in providing explanations covering topics traditionally under the ambit of philosophy has caused much reflection as to the new role for philosphy as a 'hand-maiden' to science. Such thinking was most influentially taken up by the nascent 'philosophers of language', such as Whitehead, Russell and Moore, and later by neo-positivists of the Vienna Circle, in controversially defining philosophy's role as solely clarifying the concepts and language of the sciences. And for the first half of the 20th-century this was largely the purview of philosophy of science. However, this delimited role has never been accepted universally, and a range of themes emerged as salient to a philosophy no longer vying to offer explanations of existence and nature on par with the success of post-Newtonian physics, yet still important as a reflective, clarifying and at times corrective 'avuncular branch' of the sciences. Such general themes include: the nature of this mutual relationship; the constitution of explanation, causation and laws; the inter-relationship between conceptual changes and scientific theories; the testing of scientific hypotheses; and science in social context and the impact of society and history. After Kuhn's work regarding conceptual change, this last current eventually matured into concerns of constructivist philosophy and sociology of science as well into the branches of philosophy of the social sciences and science studies.

Within these general concerns, two 'camps' may be identified. One major grouping, under methodology, is closely related to the theory of knowledge, and explores the methods by which the sciences arrive at posited truths about the world, as well as opening the rationale for these methods to inquiry. Under this grouping, questions regarding the nature of the relationship between confirmation of a theory and the underpinning evidence and hypothesis or how observational data might falsify a hypothesis are raised. Another grouping, aligned more closely with philosophy of language and metaphysics, explores the meaning and content of scientific results. Questions may range from the structure of scientific explanations, cognitive content of 'hypostatized' phenomena to the nature of scientific laws. Additionally, many problems are examined which arise out of specific contexts of scientific practice.

For archaeology, the work of the philosophers of science has historically drawn only minor attention. With the 'new archaeology', conscious attempts were made to emulate the attitude of the neo-positivists, thus incorporating 'philosophy' in order to clarify hypotheses and 'truth-statements'. Primarily the discussions of Popper and later Nagel and Hempel were introduced into archaeology to help define terms and language, structure observation and falsification procedures, and argue for the scientific nature of archaeology - along with the social sciences and history (eg. Hempel). Thus the outlook of the neo-positivists, which had gained ascendency in the 1920's and 1930's, was consciously adopted by the new archaeologists in the 1960's and 1970's. Of course by this time, philosophy of science had diverged from the Vienna Circle characterization, and then contemporary debates in philosophy of science had resoundly become post-positivist in nature, ranging from Kuhn's paradigmatic shifts to Feyerabend's anarchist science to the re-introduction of continental philosophy topics and perspectives. This rapprochement with philosophy of science has been somewhat updated by post-processual linkages, and again most recently with a consideration of science studies and 'technoscience thinking' and its implications for archaeology.