 First, reflecting judgment enables us to discover empirical laws of nature by leading us to regard nature as if it were the product of intelligent design (5:179–186). We do not need reflecting judgment to grasp the a priori laws of nature based on our categories, such as that every event has a cause. But in addition to these a priori laws nature is also governed by particular, empirical laws, such as that fire causes smoke, which we cannot know without consulting experience. To discover these laws, we must form hypotheses and devise experiments on the assumption that nature is governed by empirical laws that we can grasp (Bxiii–xiv). Reflecting judgment makes this assumption through its principle to regard nature as purposive for our understanding, which leads us to treat nature as if its empirical laws were designed to be understood by us (5:180–181). Since this principle only regulates our cognition but is not constitutive of nature itself, this does not amount to assuming that nature really is the product of intelligent design, which according to Kant we are not justified in believing on theoretical grounds. Rather, it amounts only to approaching nature in the practice of science as if it were designed to be understood by us. We are justified in doing this because it enables us to discover empirical laws of nature. But it is only a regulative principle of reflecting judgment, not genuine theoretical knowledge, that nature is purposive in this way.