Online research in philosophy

In his "Ontological proof", Kurt Gödel introduces the notion of a second-order value property, the positive property P. The second axiom of the proof states that for any property φ: If φ is positive, its negation is not positive, and vice versa. I put forward that this concept of positiveness leads into a paradox when we apply it to the following self-reflexive sentences: (A) The truth value of A is not positive; (B) The truth value of B is positive. Given axiom 2, sentences A and B paradoxically cannot be both true or both false, and it is also impossible that one of the sentences is true whereas the other is false.

A solid grasp of the main themes and arguments of the seventeenth century philosopher Rene Descartes is an essential tool towards understanding modern thought, and a necessary entree to the work of the empiricists and Immanuel Kant, and to the study of contemporary epistemology and philosophy of mind. Clear and accessible, this book serves as an introduction to Descartes's ideas for undergraduates and as a sophisticated companion to his Meditations for more advanced readers. After a thorough discussion of the main themes and arguments of the Meditations, the historical background of the work, and its critical reception, the author offers his own reflections on Cartesian doubt, the cogito, the causal and ontological proofs of God's existence, the Cartesian circle, Cartesian dualism, and Descartes' views of the material world. The commentary includes and cross-references the full text of Meditations I, II, and V, and most of Meditations III and VI, employing John Cottingham's highly-praised translation.

This paper provides an interpretation and evaluation of Spinoza’s highly original version of the ontological proof in terms of the concept of substance instead of the concept of perfection in the first book of his Ethics. Taking the lead from Kant’s critique of ontological arguments in the Critique of Pure Reason, the paper explores the underlying ontological and epistemological presuppositions of Spinoza’s proof. The main topics of consideration are the nature of Spinoza’s definitions, the way he conceives of the relation between a substance and its essence, and his conception of existence. Once clarity is shed upon these fundamental issues, it becomes possible to address the proof in its own terms. It is then easy to see that Kant’s objections miss their target and that the same is true of those advanced by another of the ontological argument’s most famous critics, Bertrand Russell. Finally, several interpretations of Spinoza’s proof are proposed and critically evaluated; on all of them, the argument turns out to be either invalid or question-begging.

It is often thought that, although Spinoza develops a bold and distinctive conception of God (the unique substance, or Natura Naturans, in which all else inheres and which possesses infinitely many attributes, including extension), the arguments that he offers which purport to prove God’s existence contribute nothing new to natural theology. Rather, he is seen as just another participant in the seventeenthcentury revival of the ontological argument initiated by Descartes and taken up by Malebranche and Leibniz among others. That this is the case is both puzzling and unfortunate. It is puzzling because although Spinoza does offer an ontological proof for the existence of God, he also offers three other non-ontological proofs. It is unfortunate because these other non-ontological proofs are both more convincing and more interesting than his ontological proof. In this paper, I offer reconstructions and assessments of all of Spinoza’s arguments and argue that Spinoza’s metaphysical rationalism and his commitment to something like a Principle of Sufficient Reason are the driving force behind Spinoza’s non-ontological arguments.

Can God be the efficient cause of himself (causa sui,)? It is well known that Descartes answers this question in the affirmative, but it is considerably less clear why. The main contention of the essay is that Descartes advances the causa sui doctrine because he came to think that the ontological proof of Meditation V required it. We argue these contentions through a close analysis of Descartes' initial articulation of causa sui in response to Caterus, followed by attention to the reformulation of the doctrine in response to the logical objections posed by Arnauld. Our understanding of causa sui as a move made within the horizon of the ontological proof not only illuminates why Descartes would have defended a doctrine as conceptually problematic as causa sui, but also provides an alternative to Jean-Luc Marion's view that causa sui constitutes a third, distinct proof for the existence of God. /// Pode Deus ser a causa eficiente de si mesmo (causa sui,)? É bem sabido que Descartes responde aflrmativamente a esta questão, mas é consideravelmente menos claro porquê. O principal conteúdo do ensaio é que Descartes apresenta a doutrina da causa sui porque pensou que a prova ontológica da Meditação V precisava dela. Demonstramos estas afirmações através de uma análise rigorosa da articulação inicial de Descartes da causa sui em resposta a Caterus, seguida de uma atenção à reformulação da doutrina em resposta às objecções logicas apresentadas por Arnauld. A nossa compreensão da causa sui como proposta feita no horizonte da prova ontológica não ilumina apenas porque é que Descartes teria defendido uma doutrina conceptualmente tão problemática como a causa sui, mas também providencia uma alternativa ao ponto de vista de Jean-Luc Marion de que a causa sui constitui a terceira, prova distintapara a existência de Deus.

Proof and perception : the context of the argumentum cartesianum -- Refutations of atheism : ontological arguments in English philosophy, 1652-1705 -- Being and intuition : Malebranche's appropriation of the argument -- An adequate conception : the argument in Spinoza's philosophy -- Ontological arguments in Leibniz and the German enlightenment -- Kant's systematic critique of the ontological argument -- Hegel's reconstruction of the argument.

In this paper, I argue that commentators have missed a significant clue given by Descartes in coming to understand his 'ontological' proof for the existence of God. In both the analytic and synthetic presentations of the proof throughout his writings, Descartes notes that the proof works 'in the same way' as a particular geometrical proof. I explore the significance of such a parallel, and conclude that Descartes could not have intended readers to think that the argument consists of some kind of intuition. I argue that for Descartes the attribute of existence is a 'second-order' attribute that is demonstrated to belong to the idea of God on the basis of 'first-order' attributes. The proof, properly understood, is in fact a demonstration. Having brought to light the geometrical parallels between the ontological and geometrical proofs, we have new evidence to resolve the 'intuition versus demonstration' controversy that has characterized much of the discussion of Descartes's ontological argument.

Abstract:  Contrary to received opinion, Descartes' view on the merits of the ontological proof may actually agree with that of Thomas Aquinas, whose rejection of the a priori existence proof has stocked the armories of anti-Anselmians ever since. In a rarely noted passage of the First Replies, Descartes claims not to differ in any respect from Thomas on the proof, a claim that gains sense in light of recent work on the Fifth Meditation. That work in turn reveals a well-founded, if surprising, understanding of the Cartesian proof and of Cartesianism's true relation to Thomism.

In this new introduction to a classic philosophical text, Catherine Wilson examines the arguments of Descartes' famous Meditations, the book which launched modern philosophy. Drawing on the reinterpretations of Descartes' thought of the past twenty-five years, she shows how Descartes constructs a theory of the mind, the body, nature, and God from a premise of radical uncertainty. She discusses in detail the historical context of Descartes' writings and their relationship to early modern science, and at the same time she introduces concepts and problems that define the philosophical enterprise as it is understood today. Following closely the text of the Meditations and meant to be read alongside them, this survey is accessible to readers with no previous background in philosophy. It is well-suited to university-level courses on Descartes, but can also be read with profit by students in other disciplines.