Around the turn of the twenty-first century, what has come to be called the new mechanical philosophy (or, for brevity, the new mechanism) emerged as a framework for thinking about the philosophical assumptions underlying many areas of science, especially in sciences such as biology, neuroscience, and psychology. In this entry, we introduce and summarize the distinctive features of this framework, and we discuss how it addresses a range of classic issues in the philosophy of science, including explanation, metaphysics, the relations between scientific disciplines, and the process of scientific discovery. For each of these issues, we show how the mechanistic framework has reoriented philosophical work, what the new mechanism has contributed to the discussion, and what remains to be done.