 There are countless effects in nature that can be deduced from the laws of nature “in many different ways”. How do we find the right way? Experiment. We start with the effects we want to explain; we isolate and manipulate these effects in order to more precisely determine the conditions under which they are produced; and then we make suppositions about what their underlying causes are based on what we know about the nature of matter and the laws of nature. Traditional deductive order is reversed; underlying causes too small to be directly observed are deduced from given effects. Descartes describes his procedure for deducing causes from effects toward the end of Discourse VI: