Philosophy of science studies the foundations, methods, and implications of science. It asks what science is, how it works, and what it can tell us about the world. It is not the same as science itself. Scientists do science. Philosophers of science ask what science presupposes and what it achieves. The field emerged as a distinct discipline in the 20th century, with the logical positivists of the Vienna Circle attempting to ground science in empirical verification. That program collapsed, but it set the agenda for decades of debate.

Key questions include: What is a scientific explanation? What makes a theory good? How do theories change? Is there a scientific method? How do observation and theory relate? Karl Popper argued that falsifiability is the mark of science. Thomas Kuhn argued that science proceeds through paradigms and revolutions. Imre Lakatos proposed research programs. Paul Feyerabend argued that there is no single method. The field also examines specific sciences: physics, biology, neuroscience, economics. It asks about the nature of causation, laws, models, and evidence. Philosophy of science matters because science is one of the most powerful ways of knowing, and understanding how it works helps us use it well.

Key topics

• Demarcation. What distinguishes science from non-science?
• Explanation. What makes an explanation scientific?
• Theory change. How do scientific theories develop?
• Realism. Do scientific theories describe reality?
• Method. Is there a scientific method?

Philosophy of science is not the same as the history of science, though the two are closely related. History describes what happened. Philosophy asks what it means.