Popper’s Legacy: What Is Science?

What is science? is not a philosophical question. At least in the context of this book, it is a practical question: how does science proceed, what makes it reliable, what are its limitations? Insofar as there is a theory, it comprises a lineage starting in the 17th century with Francis Bacon (who argued that science proceeds by analyzing data) and René Descartes (who argued that science should be driven by hypotheses). The ideas of Thomas Kuhn and Karl Popper had a significant influence in the 20th century. Kuhn changed the understanding of how science proceeds by describing ‘revolutions’ that alternate with periods of incremental advance. The concept that revolutions overthrow paradigms has become embedded in science. If there is any philosopher whom scientists themselves most often acknowledge, it is Karl Popper for his famous argument that no hypothesis is valid in science unless it’s possible in principle to falsify it. Popper’s legacy was to define a focal point distinguishing science from other intellectual activities. Science itself has become so diverse that it’s difficult otherwise to define its limits. It may seem trite—and it will certainly infuriate modern day philosophers—but a simple description might be that scientists have a religion: it is called Truth.