The history and philosophy of science (HPS) is an academic discipline that encompasses the philosophy of science and the history of science. Although many scholars in the field are trained primarily as either historians or as philosophers, there are degree-granting departments of HPS at several prominent universities. Though philosophy of science and history of science are their own disciplines, history and philosophy of science is a discipline in its own right.
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultimate purpose of science. This discipline overlaps with metaphysics/ontology and epistemology, for example, when it explores the relationship between science and truth. Philosophy of science focuses on metaphysical, epistemic and semantic aspects of science. Ethical issues such as bioethics and scientific misconduct are often considered ethics or science studies rather than philosophy of science.
There is no consensus among philosophers about many of the central problems concerned with the philosophy of science, including whether science can reveal the truth about unobservable things and whether scientific reasoning can be justified at all. In addition to these general questions about science as a whole, philosophers of science consider problems that apply to particular sciences (such as astronomy, biology, chemistry, Earth science, or physics). Some philosophers of science also use contemporary results in science to reach conclusions about philosophy itself.
One origin of the unified discipline is the historical approach to the discipline of the philosophy of science. This hybrid approach is reflected in the career of Thomas Kuhn. His first permanent appointment, at the University of California, Berkeley, was to a position advertised by the philosophy department, but he also taught courses from the history department.