Kant and the Laws of Nature

Immanuel Kant’s complex and nuanced view on the laws of nature has been at the center of renewed attention among Kant scholars since the late 20th century. Kant’s view is one of the best examples in the Early Modern period of the philosophical view of nature as “ordered” and “lawful” that emerged with the scientific advancements of the 17th and 18th centuries. Building on the extraordinary success of Isaac Newton’s mechanics and optics, but also on the burgeoning chemistry of Stephen Hales in England and Herman Boerhaave and Pieter van Musschenbroek in the Netherlands, among many others, Kant’s lifelong engagement with the natural sciences (broadly construed) influenced and fed into his mature Critical-period philosophy. Explaining why laws of nature seemingly govern the natural world (as much as the moral law regulates the realm of human freedom and choice) is key to Kant’s transcendental philosophy. Kant seems to embrace a coherent account of what it is to be a law, in moral philosophy and in theoretical philosophy. When it comes to theoretical philosophy (and in particular, to Kant’s philosophy of nature, which is our topic), the main question is how it is possible for us to come to know nature as ordered and lawful. Where does the lawfulness of nature come from? In the Critique of Pure Reason and in the Prolegomena, Kant held the view that our faculty of understanding is the primary source of nature’s lawfulness because the a priori categories of the understanding “prescribe laws to nature”—that is, they play the role of constitutive a priori principles for our experience of nature. Yet, already in the first Critique, and even more so in Critique of the Power of Judgment, Kant stressed the importance of the faculty of reason, first, and the faculty of reflective judgment, second—with their regulative principles—in offering a system of laws necessary for our knowledge of nature. The crucial distinction between constitutive principles of the understanding versus regulative principles of reason and reflective judgment leads, in turn, to a series of further distinctions in Kant’s philosophy. For example, it leads to the different status of laws in the physical sciences and in the life sciences, which in turn became the battleground for the debate concerning mechanical explanations versus teleological explanations.