Christia Mercer

This essay examines the basis of Leibniz’s views on the unity of corporeal substance. It draws on the analysis of Robert Sleigh, who linked the unity of Leibnizian substances to their possession of identity through change. It argues that Sleigh’s analysis leaves many questions about unity unanswered, notably the problem of how a substantial form produces unity in its associated passive principle or body, whose components are in constant flux. The key to this problem lies in a historically informed account of Leibniz’s writings, which reveal his underlying assumptions on unity.

Descartes intended to revolutionize seventeenth-century philosophy and science. But first he had to persuade his contemporaries of the truth of his ideas. Of all his publications, Meditations on First Philosophy is methodologically the most ingenuous. Its goal is to provoke readers, even recalcitrant ones, to discover the principles of “first philosophy.” The means to its goal is a reconfiguration of traditional methodological strategies. The aim of this chapter is to display the methodological strategy of the Meditations. The text’s method is more subtle and more philosophically significant than has generally been appreciated. Descartes’ most famous work is best understood as a response to four somewhat separate philosophical concerns extant in the seventeenth century. Section 1 describes these. Section 2 discusses how Descartes uses and transforms them. A clearer sense of the Meditations’ methodological strategy provides a better understanding of exactly how Descartes intended to revolutionize seventeenth-century thought.

The Preface to Leibniz's famous Theodicy offers a perspective on the work that has been insufficiently studied. In this paper, I ask that we step back from the main text of the Theodicy and attend to its Preface. I show that the latter performs two crucial preparatory tasks that have not been properly appreciated. The first is to offer a public declaration of what I call Leibniz’s radical rationalism. The Preface assumes that any attentive rational being is capable of divine knowledge. The basic idea is that it is knowledge about a divine perfection that can be understood more or less completely. In the Preface, Leibniz entices his readers to seek such knowledge and explains why doing so has been so difficult before now. What makes this rationalism radical is that divine knowledge is severed from any religion or set of religious beliefs. While some Christian doctrines make it easier to approach God, they are neither necessary nor sufficient to do so. The author of the Theodicy thereby informs his readers that they have access to divine perfections, regardless of religious affiliation. To acquire such knowledge, they need only work through his book. The second task of the Preface is closely related to the first. It invites readers to seek divine love and virtue. To set themselves on the path to virtue, they need only avoid the pitfalls of religion and use reason in the right way to grasp a divine perfection. Once they enter the main text of the Theodicy, they have begun that journey.

This book offers a major reassessment of Leibniz's metaphysics. Christia Mercer has exposed the underlying doctrines of Leibniz's philosophy. By analysing Leibniz's early works she demonstrates that the metaphysics of pre-established harmony developed many years earlier than previously believed and for reasons which have not been understood. As a result of this analysis she has unearthed a philosophical school that Leibniz scholars have not recognized. A much deeper understanding of some of Leibniz's key doctrines emerges. Moreover, since the Leibniz that is revealed here does not fit neatly into the standard accounts of the history of philosophy and science, Christia Mercer's study will prompt scholars to reconsider their basic assumptions about early modern philosophy and science.

Despite what you have heard over the years, the famous evil deceiver argument in Meditation One is not original to Descartes. Early modern meditators often struggle with deceptive demons. The author of the Meditations is merely giving a new spin to a common rhetorical device. Equally surprising is the fact that Descartes’ epistemological rendering of the demon trope is probably inspired by a Spanish nun, Teresa of Ávila, whose works have been ignored by historians of philosophy, although they were a global phenomenon during Descartes’ formative years. In this paper, I first answer the obvious question as to why previous early modernists have missed something so important as the fact that Descartes’ most famous publication relies on a well-established genre and that his deceiver argument bears a striking similarity to ideas in Teresa’s final work, El Castillo Interior? I discuss the meditative tradition at the end of which Descartes’ Meditations stands, present evidence to support the claim that Descartes was familiar with Teresa’s proposals, contrast their meditative goals, and make a point-by-point comparison between the meditative steps in Teresa’s Interior Castle and those in Descartes’ Meditations which constitute their common deceiver strategy. My conclusion makes a case for a broader and more inclusive history of philosophy.