Ashton Green (University of Notre Dame)
In the early years of her research, Du Châtelet used the principle of sufficient reason (PSR) to develop a epistemological method, so that she could extrapolate from empirical data (such as the results of experiments in heating metals) in a rigorous way. Her goal was to attain knowledge of the hidden causes of the data. In this presentation, I will outline her method for this extrapolation, its assumptions, and consider the implications of such a view.
According to Du Châtelet's method, any metaphysical claim, such as one concerning what substances make up the fundamental physical level, much be anchored in types of evidence which Du Châtelet considers reliable. Du Châtelet considers evidence reliable when it takes several forms. First, when it comes directly from empirical data, which is more rigorous than sense data, because it involves repeated and well-organized experimentation. But also, Du Châtelet also considers "principles" to be reliable epistemological tools, such as the law of non-contradiction, the principle of sufficient reason, and the principle of continuity, in addition to empirical data.
For this reason, I call her mature position (after 1740) Principled Empiricism. In Principled Empiricism, beliefs are justified if they are based on reliable evidence of the following two kinds: empirical data, and what she calls “self-evident principles”. According to this method, beliefs based only on one or the other of these types of evidence, as well as both in conjunction, are justified. This allows her to make metaphysical hypotheses while still adhering to her Principled Empiricism, in which all knowledge is either self-evident, empirically confirmed, or built directly by those two pieces.
By using the PSR as the principle which governs contingent facts, and is therefore appropriate to thy physical world, Du Châtelet's method extrapolates beyond empirical data, hypothesizing the best “sufficient reasons” for the effects gathered in empirical study. Sufficient reasons, however, according to Du Châtelet, are restricted to the most direct cause in the mechanical order of the physical world. Two parts of this definition need to be defended. First Du Châtelet must defend that the physical world is mechanical, and define what exactly she means by mechanical. Second, she must defend that in fact, the physical world consists of one mechanical system, and only one, of which all causes and effects are a part. If she is able to do this successfully, she can bring explanations of all phenomena into one “machine [of] mutual connection,” her new system will justify requiring mechanical explanations for all phenomena. She considers these arguments to be based on the PSR.
In addition to establishing how Du Châtelet applied the PSR to her project, I discuss the problematic aspects of her restriction of explanations to mechanical ones, based on her premise that the universe is a single machine. Finally, I consider contemporary analogs to her position, and the difference between their foundations and Du Châtelet's.
