The problem of unifying knowledge represents the frontier between science and philosophy. Science approaches the problem analytically bottom-up whereas, prior to the end of the nineteenth century, philosophy approached the problem synthetically top-down. In the late nineteenth century, the approach of speculative metaphysics was rejected outright by science. Unfortunately, in the rush for science to break with speculative metaphysics, synthetic or top-down philosophy as a whole was rejected. This meant not only the rejection of speculative metaphysics, but also the implicit (...) rejection of empirically-led synthetic philosophy and the philosophy of nature. Since a change in the paradigm of science requires a change in the philosophy of nature underpinning science, the rejection of the philosophy of nature closes science to the possibility of a paradigm change. Given the foundational problems faced by science, there is a need for empirically-led synthetic philosophy in order to discover a new empirically-based philosophy of nature. Such a philosophy of nature may open science to the possibility of a paradigm change. (shrink)