In his defense of innateness in New Essays on Human Understanding (1704), Leibniz attributes innateness to concepts and principles which do not originate from the senses rather than to the ideas that we are born with. He argues that the innate concepts and principles can be known in two ways: through reason or natural light (necessary truths), and through instincts (other innate truths and principles). In this paper I will show how theoretical and moral reasoning differ from each other in Leibniz, and compare moral reasoning and instincts as sources of knowledge in his practical philosophy. As the practical instincts are closely related to pleasure and passions, which are by nature cognitive, my emphasis will be on the affective character of instinctive moral action and especially deliberation which leads to moral action. I will argue that inclinations arising from moral instinct, which lead us to pleasure while avoiding sorrow, can direct our moral action and sometimes anticipate reasoning when conclusions are not readily available. Acting by will, which is related to moral reasoning, and acting by instincts can lead us to the same moral knowledge independently, but they can also complement each other. To illustrate the two alternative ways to reach moral knowledge, I will discuss the case of happiness, which is the goal of all human moral action for Leibniz.

While contemporary accounts understand esteem and self-esteem as essentially competitive phenomena, early modern natural law theorists developed a conception of justified esteem and self-esteem based on naturally good character traits. This article explores how such a normative conception of esteem and self-esteem is developed in the work of Christian Wolff (1679–1754). Two features make Wolff’s approach distinctive: (1) He uses the analysis of common notions that are expressed in everyday language to provide a foundation for the aspects of natural law on which his conception of natural duties of esteem depends. (2) He develops a non-competitive conception of esteem and self-esteem into a cooperative conception, according to which enhancing the esteem in which others are held is seen as a tool for promoting self-perfection. Wolff’s ideas offer a solution to the well-known problems connected with competitive life-styles, and at the same time assign a central role in moral motivation to the desire of being esteemed and of having high self-esteem. Moreover, due to his emphasis on presenting a philosophical analysis based on common notions, he offers a solution that is meant to be persuasive from the perspective of everyday morality.

This essay examines René Descartes’ Meditations on First Philosophy. It argues that the evil genius is the meditator who narrates Meditations and that Descartes’ goal in Meditation One is to transform his readers into evil geniuses. This account of the evil genius is significant because it explains why the evil genius must be finite and why it cannot call mathematics or logic into doubt. Further, it highlights the need to read the Meditations on two levels—one examining the meditator’s line of thinking on its own terms and the other exploring Descartes’ reasons for depicting the meditator’s progress in the way that he does.

This essay explores the parallel development of fencing theory and philosophy in early modern Europe, and suggests that each field significantly influenced the other. Arguably, neither philosophy nor fencing would be the same today had the two not been engaged in this particular cultural symbiosis. An analysis is given of the philosophic content within several historical fencing treatises and of the position of fencing in seventeenth and eighteenth-century education and courtly life. Two case studies are then examined: the influence of the fencing master Charles Besnard on the intellectual development of Descartes, and the fencing master William Hope’s appropriation of the ideas of John Locke.

For Erasmus, the two fountains streaming milky juice—a new mother’s breasts—represent powerful symbols of love and authority. Erasmus describes the mother’s breasts as fountains oozing love to the sucking child. Elizabeth Clinton extends the image of Mother to represent God, reminding the nursing mother that when she looks on her sucking child, she should remember that she is God’s new born babe, sucking His instruction and His word, even as the babe sucks her breast. Dorothy Leigh extends the image of the nursing mother to an image of Christ himself. Mother’s love, especially a breast-feeding or “lying in” mother’s love, is one of the most authoritatively gendered representations of love. Issues of gender and authority converge often around the image of the breast-feeding mother. Drawing on the image of the nursing mother, Dorothy Leigh and other early modern writers actively engaged in the most contentious and public debates of their day, including the authority of men, preachers and kings.

The origins of demography as a scientific discipline are usually seen as intimately connected to the organisational and economic needs of the early modern state. This paper, by contrast, presents an early demographic enterprise that falls outside this framework. The calculations performed by the Italian Jesuit Giovanni Battista Riccioli in an appendix to his Geographia et hydrographia reformata (“Geography and hydrography brought up to date,” 1661) are the first systematic attempt presently known to arrive at an estimate of the entire world population. Yet they appear to have no political purpose and rather belong to a learned, bookish tradition of demographical thinking that may be termed “humanist”. The article starts from a summary of Riccioli’s life, of the book wherein his demographic exercise is contained and of this exercise itself. Thereafter, Riccioli’s motives, sources, methodology and results are discussed. By way of conclusion, some preliminary reflections on the place of Riccioli and the humanist tradition in the early modern history of demography as a whole are offered. Two appendices present a translation of the Coniectura and tabulate its literary sources in order to provide some possible starting points for a study of the aforementioned tradition.

In The Sea–Mans Kalendar (1636 [1638?]), Henry Bond predicted that magnetic declination would be 0° in 1657, and would then increase westerly for (at least) 30 years. Based on these predictions, Bond went on to claim in The Longitude Found (1676) that, by using his model of magnetism, he can offer a technique for determining longitude. This paper offers an assessment of Bond’s method for longitude determination and critically evaluates Thomas Hobbes’s so–far neglected response to Bond’s proposal in Decameron physiologicum (1678), in which Hobbes complains about what he takes to be Bond’s implicit natural philosophy and about his use of spherical trigonometry.

Though he is known primarily for his mathematics, John Wallis (1616–1703) was also a prominent natural philosopher and experimentalist. Like many experimental philosophers, including his colleagues in the Royal So­ciety, Wallis sought to identify the mathematical laws that govern natural phenomena. However, I argue that Wallis’s particular understanding of the laws of nature was informed by his reading of a thirteenth–century optical treatise by Robert Grosseteste, De lineis, angulis et figuris, which expresses the principle that “Nature doth not work by Election.” Wallis’s use of this principle in his Discourse of Gravity and Gravitation (1675) helps to clarify his understanding of natural laws. According to Wallis, since nature cannot choose to act one way or another, natural phenomena are unfailingly regular, and it is this that allows them to be predicted, generalized, and described by mathematical rules. Furthermore, I argue that Wallis’s reading of Grosseteste reveals one way that medieval scholarship contributed to the “mathematization of nature” in the early modern period: historically–minded scholars like Wallis found insightful philosophical principles in medieval sources, and they transformed and redeployed these principles to suit the needs of early modern natural philosophy.

The early history of thermometry is most commonly described as the result of a continuous development rather than the product of a single brilliant mind, and yet scholars have often credited the Italian physician Santorio Santori (1561–1636) with the invention of the first thermometers. The purpose of using such instruments within the traditional context of Galenic medicine, however, has not been investigated and scholars have consistently assumed that, being subject to the influence of atmospheric pressure and en­vironmental heat, Santorio’s instruments provided unreliable measurements. The discovery that, as early as 1612, Santorio describes all vacuum-related phenomena as effects of the atmospheric pressure of the air, provides ample room for reconsidering his role in the development of precision instruments and the early history of thermometry in particular. By drawing on a variety of written and visual sources, some unpublished, in the first part of this article I argue that Santorio’s appreciation of phenomena related to the weight of the air allowed him to construct the first thermometers working as sealed devices. Finally, in the second part, I consider Santorio’s use of the thermometer as related to the seventeenth-century medical practice and his way to measure the temperature as based on a wide sample of individuals.

I analyze in this article the different ways in which Descartes uses abstraction in the Regulæ, discussing his project of a mathematical physics, the role of the imagination, and the status of numbers. I also try to show that the doctrine of simple natures cannot be well accommodated with the theory of abstraction developed in Rule 14, having instead a greater affinity with Descartes’ later theory of abstraction and exclusion (from the period after the Meditationes), in which imagination plays no role and everything happens at a strictly intellectual level. This interpretation is supported by the recent discovery of the Cambridge manuscript, which almost certainly records an early stage of composition and in which the doctrine of simple natures is absent, thus being very probably a later development.