This chapter begins with a discussion of humanist criticisms of scholastic logic. It then discusses the evolution of the scholastic tradition and the influence of Renaissance Aristotelianism, Descartes and his influence, the Port-Royal Logic, the emergence of a logic of cognitive faculties, logic and mathematics in the late 17th century, Gottfried Wilhelm Leibniz’s role in the history of formal logic, and Kant’s influence on logic.
The Rationalists: Descartes, Spinoza and Leibniz
Publisher’s Note: Descartes, Spinoza and Leibniz stand out among their seventeenth-century contemporaries as the great rationalist philosophers. Each sought to construct a philosophical system in which theological and philosophical foundations serve to explain the physical, mental and moral universe. Through a careful analysis of their work, Pauline Phemister explores the rationalists seminal contribution to the development of modern philosophy. Broad terminological agreement and a shared appreciation of the role of reason in ethics do not mask the very significant disagreements that led to three distinctive philosophical systems: Cartesian dualism, Spinozan monism and Leibnizian pluralism. The book explores the nature of, and offers reasons for, these differences. Phemister contends that Spinoza and Leibniz developed their systems in part through engagements with and amendment of Cartesian philosophy, and critically analyses the arguments and contributions of all three philosophers. The clarity of the authors discussion of their key ideas including their views on knowledge, universal languages, the nature of substance and substances, bodies, the relation of mind and body, freedom, and the role of distinct perception and reason in morals will make this book the ideal introduction to rationalist philosophy
Arguments by Leibniz’s Law in Metaphysics
Abstract: Leibniz’s Law (or as it sometimes called, ‘the Indiscerniblity of Identicals’) is a widely accepted principle governing the notion of numerical identity. The principle states that if a is identical to b, then any property had by a is also had by b. Leibniz’s Law may seem like a trivial principle, but its apparent consequences are far from trivial. The law has been utilised in a wide range of arguments in metaphysics, many leading to substantive and controversial conclusions. This article discusses the applications of Leibniz’s Law to arguments in metaphysics. It begins by presenting a variety of central arguments in metaphysics which appeal to the law. The article then proceeds to discuss a range of strategies that can be drawn upon in resisting an argument by Leibniz’s Law. These strategies divide into three categories: (i) denying Leibniz’s Law; (ii) denying that the argument in question involves a genuine application of the law; and (iii) denying that the argument’s premises are true. Strategies falling under each of these three categories are discussed in turn.
Leibniz on Causation, Part 1
Abstract: Leibniz holds that created substances do not causally interact with each other but that there is causal activity within each such creature. Every created substance constantly changes internally, and each of these changes is caused by the substance itself or by its prior states. Leibniz describes this kind of intra-substance causation both in terms of final causation and in terms of efficient causation. How exactly this works, however, is highly controversial. I will identify what I take to be the major interpretive issues surrounding Leibniz’s views on causation and examine several influential interpretations of these views. In ‘Leibniz on Causation – Part 2’ I will then take a closer look at final causation.
Gottfried Leibniz [on Free Will]
Abstract: Leibniz was obsessed with freedom. He turns to this topic again and again throughout his long career. And what he has to say about freedom is much more resourceful and inventive than typically acknowledged. While building on medieval theories—for instance by describing freedom in terms of the relation between the agent’s will and intellect—he also adds radically new elements and even anticipates some views that are popular today. The combination of theses about free will that Leibniz endorses in his mature writings is unusual and may at first appear inconsistent: (a) he claims that some of our actions are free, (b) he links free agency closely to agent causation and in fact appears to deny that there is event causation; (c) he accepts a form of determinism. In other words, Leibniz endorses what we can describe as an agent-causal compatibilist theory of freedom. The three theses may seem to be in tension not only because proponents of agent causation views are typically incompatibilists, but also because determinism is often defined in a way that presupposes event causation. As we will see soon, however, the tension is merely apparent. Leibniz’s version of agent-causal compatibilism is perfectly coherent and has some unique advantages over rival accounts.
Gottfried Leibniz: Philosophy of Mind
Abstract: Gottfried Wilhelm Leibniz (1646-1716) was a true polymath: he made substantial contributions to a host of different fields such as mathematics, law, physics, theology, and most subfields of philosophy. Within the philosophy of mind, his chief innovations include his rejection of the Cartesian doctrines that all mental states are conscious and that non-human animals lack souls as well as sensation. Leibniz’s belief that non-rational animals have souls and feelings prompted him to reflect much more thoroughly than many of his predecessors on the mental capacities that distinguish human beings from lower animals. Relatedly, the acknowledgment of unconscious mental representations and motivations enabled Leibniz to provide a far more sophisticated account of human psychology. It also led Leibniz to hold that perception—rather than consciousness, as Cartesians assume—is the distinguishing mark of mentality.
Leibniz on Causation, Part 2
Abstract: Leibniz is almost unique among early modern philosophers in giving final causation a central place in his metaphysical system. All changes in created substances, according to Leibniz, have final causes, that is, occur for the sake of some end. There is, however, no consensus among commentators about the details of Leibniz’s views on final causation. The least perfect types of changes that created substances undergo are especially puzzling because those changes seem radically different from paradigmatic instances of final causation. Building on my more general discussion of efficient and final causation in ‘Leibniz on Causation – Part 1,’ I will examine and assess some of the rival interpretations of Leibniz’s account of final causation.
Selections from the Principles of the Most Ancient and Modern Philosophy
Anne Conway’s treatise is a work of Platonist metaphysics in which she derives her system of philosophy from the existence and attributes of God. The framework of Conway’s system is a tripartite ontological hierarchy of ‘species’, the highest of which is God, the source of all being. Christ, or ‘middle nature’, links God and the third species, called ‘Creature’. […] Anne Conway denies the existence of material body as such, arguing that inert corporeal substance would contradict the nature of God, who is life itself. Incorporeal created substance is, however, differentiated from the divine, principally on account of its mutability and multiplicity even so, the infinite number and constant mutability of created monads constitute an obverse reflection of the unity, infinity, eternity and unchangeableness of God. The continuum between God and creatures is made possible through ‘middle nature’, an intermediary being, through which God communicates life, action, goodness and justice. […] The spiritual perfectionism of Anne Conway’s system has dual aspect: metaphysical and moral. On the one hand all things are capable of becoming more spirit-like, that is, more refined qua spiritual substance. At the same time, all things are capable of increased goodness. She explains evil as a falling away from the perfection of God, and understands suffering as part of a longer term process of spiritual recovery. She denies the eternity of hell, since for God to punish finite wrong-doing with infinite and eternal hell punishment would be manifestly unjust and therefore a contradiction of the divine nature. Instead she explains pain and suffering as purgative, with the ultimate aim of restoring creatures to moral and metaphysical perfection. Anne Conway’s system is thus not just an ontology and but a theodicy (From SEP.)