Life and works -- Cartesian doubt -- Cogito ergo sum -- Sum res cogitans -- Ideas -- The idea of god -- The ontological argument -- Reason and intuition -- Matter and motion zoo -- Mind and body.

"This stunning work is without question a major contribution to Cartesian studies, to the field of early modern philosophy, and to general epistemology--original, provocative, and philosophically interesting.

In this classic work, best-selling author Harry Frankfurt provides a compelling analysis of the question that not only lies at the heart of Descartes's Meditations, but also constitutes the central preoccupation of modern philosophy: on what basis can reason claim to provide any justification for the truth of our beliefs? Demons, Dreamers, and Madmen provides an ingenious account of Descartes's defense of reason against his own famously skeptical doubts that he might be a madman, dreaming, or, worse yet, deceived by (...) an evil demon into believing falsely.Frankfurt's masterful and imaginative reading of Descartes's seminal work not only stands the test of time; one imagines Descartes himself nodding in agreement. (shrink)

I argue that descartes thinks he can be metaphysically certain about each premise in the argument for god's existence, Even before he draws the argument's final conclusion that all his distinct ideas are metaphysically certain. The certainty of the personal premises is secured in the second meditation. The certainty of the causal premises, I argue, Arises from their central role in generating reasons for doubt of the kind that interest descartes.

This paper suggests that the appearance of circularity in descartes' arguments is due to a lack of precision in his statements of them, Rather than to any flaw in his reasoning. The clear and distinct perceptions presupposed in the demonstrations of the existence of God are not the same as those whose reliability depends upon the existence of god. He is presupposing the reliability only of those clear and distinct perceptions which are known through the light of nature and have (...) metaphysical certainty in that they cannot be imagined false even on the demon hypothesis. And the only clear and distinct perceptions whose reliability he is demonstrating are those which are not known through the light of nature with metaphysical certainty but are subject to metaphysical doubt on the demon hypothesis, Even though they have moral or psychological certainty. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Descartes’ Natural Light ReconsideredDeborah Boyle1. INTRODUCTIONThe “natural light” occupies an important position in Descartes’ Third Meditation, where the meditator invokes it to provide the premises needed for his proof for the existence of a non-deceiving God. Descartes also refers to the natural light throughout his Replies to the Objections to the Meditations and in the Principles of Philosophy. Yet he says almost nothing about what the natural light is (...) supposed to be, apparently assuming that his readers already know what he means. English-speaking commentators on Descartes have said little about the natural light,1 and although French commentators have paid slightly more attention to this topic, they have nonetheless provided no detailed analysis of the concept of the natural light and the role it plays in Descartes’ Meditations.2In 1973, however, John Morris published an article entitled “Descartes’ Natural Light” in the Journal of the History of Philosophy, later reprinted in Eternal Truths and the Cartesian Circle.3 Morris argues that “the understanding can be regarded in an active and a passive sense, ”4 and that the natural light should [End Page 601] be equated with the passive function of the intellect. The natural light, he asserts, isa power of cognition, which contrasts with the “active” power of conceiving. Unlike this power, it does not form ideas, or bring them to consciousness. Instead, it simply gives a click of recognition when a true idea is brought before it.5However, the textual evidence for Morris’ interpretation of the natural light is slender, and in fact the texts support a quite different reading. I shall point out some problems with Morris’ reading, and offer the beginnings of an alternative account.2. ACTIVITY, PASSIVITY, AND THE MINDIn the Fourth Meditation, Descartes draws a distinction between two faculties of mind: intellect and will. Intellect, he says, allows him “to perceive the ideas which are subjects for possible judgements” (CSM II 39/AT VII 5),6 while the will “simply consists in our ability to do or not do something (that is, to affirm or deny, to pursue or avoid)” (CSM II 40/AT VII 57). Although he does not say so in the Fourth Meditation, Descartes suggests in two 1641 letters to Regius that the intellect is passive and the will is active; strictly speaking, he says, “understanding [intellectio] is the passivity of the mind and willing [volitio] is its activity” (CSMK III 182/AT III 372). A few months later, he writes that “we should use the term ‘action’ for what plays the role of a moving force, like volition in the mind, while we apply the term ‘passion’ to what plays the role of something moved, like intellection [intellectio] and vision in the same mind” (CSMK III 199/AT III 454–5). And in the Passions of the Soul Descartes states that while volitions are actions, “the various perceptions or modes of knowledge present in us may be called its passions, in a general sense” (CSM I 335/AT XI 342).In his early work, the Rules for the Direction of the Mind, Descartes does refer to “actions of the intellect.”7 If we do not allow for changes in Descartes’ thinking, we might assume that at the time of the Meditations, too, he would be willing to speak of “actions of the intellect.” But Descartes provides no account of the [End Page 602] will in the Rules; thus any activity he might have attributed to the mind would have to be included in the role of the intellect. In the Meditations, Descartes’ philosophy of mind has expanded to provide a place for the will, which can take over the active functions previously assigned to the intellect.John Morris’ reading of the role of the natural light in the Meditations takes as its starting point a passage in the Rules where Descartes claims that the intellect itself, the cognitive power or vis cognoscens, has both active and passive functions; it is, he says, sometimes like a seal, sometimes like wax.8 After describing the various functions of the cognitive power, Descartes concludes that “according to its different functions, then, the same power is... (shrink)

The author argues that Descartes is not trapped inside the Cartesian circle. The essay rehearses Descartes’ argument against the “evil demon” hypothesis. The so-called Cartesian circle is described and some of the most prominent discussions of the problem are evaluated. Such arguments tend either to leave Descartes in the circle, or themselves depend upon distinctions that in the end lead to Descartes claiming something less than metaphysical certainty for his system. The author argues that Descartes’ real Archimedian point is the (...) light of nature, and that his project is to extend the certainty of the light of nature to those ideas which are clear and distinct. Using this interpretation of Descartes, the author returns to the accounts of the critics to account for their mischaracterization of Descartes’ reasoning as circular. (shrink)

The problem of the Cartesian Circle has been with us ever since the publication of the Meditations. This is quite remarkable, since the error of circularity which Descartes is accused of having committed is not a subtle one but is, if there is such an error, a gigantic blunder which is not difficult to discover, which was pointed out to Descartes shortly after the Meditations appeared, and which completely undermines Descartes’ primary project, the establishment of sure and certain knowledge. It (...) is incredible that Descartes, a slow and careful thinker with considerable philosophical talent, could have made such an obvious and egregious error. It is much more plausible that there really is no circularity in Descartes’ argument, and that the charges of circularity grow out of a misunderstanding of Descartes’ intention or of the way in which his argument progresses.The incredible, of course, is possible, and I am not proposing that the question of the circle be resolved merely by dismissing it, nor am I suggesting that the text be ignored in order to force consistency onto Descartes’ thought. (shrink)

Suppose that in the Meditations Descartes thinks he needs to prove that his clear and distinct perceptions are true. There can be little doubt that if he does think he needs to do this, he thinks that the way to do it is to prove that ‘a non-deceiving God exists’ is true. Now suppose that Descartes does come up with such a proof. Presumably he clearly and distinctly perceives both the premisses and that ‘a non-deceiving God exists’ follows from them. (...) But that will not suffice to prove that ‘a non-deceiving God exists’ is true. For, if there is a problem about whether clear and distinct perceptions are true, then in advance of settling it, there is a problem about whether what is proved merely on the basis of clear and distinct perceptions is true. (shrink)