Descartes, Thinking, Willing

Descartes' proof that he exists is comprised of both objective and subjective dimensions. The main steps of the objective dimension are: 1. X is certain if and only if X cannot be doubted; 2. It is impossible to doubt that one is doubting; 3. Therefore, it is certain that one thinks; 4. Therefore, it is certain that one exists. The main steps of the subjective dimension are: 1. He is a willing being, i. e. he possesses the power to choose; 2. His criteria for choosing to believe X is that X is clear and distinct; 3. It is certain that he exists; 4. Therefore, it is clear and distinct that he exists; 5. Therefore, he exists. But, once Descartes begins to examine 'I will', the nature of his incorporeality becomes more problematic. For, according to his analysis, Willing is detached from his corporeality, and has wider scope than Thinking, but can be influenced by the latter. One systematization of these propositions is to distinguish Soul and Mind, which he seems to identify, with 'I will' as the most general expression of the Soul, and with Mind, i. e. 'I think', as one of its special functions. Such a concept of Soul stands in contrast to Aristotle's, which is not exclusively incorporeal, and in which volition is located in the animal part, beneath the rational part. Or, with 'I think' reserved, as is the case with Kant, for intra-psychic and, yet, impersonal functions, the Soul could be conceived as consisting of subjective and objective divisions, i. e. 'I will' and 'I think', respectively. In any case, the Thinking-Willing relation seems to present Descartes with some systematic complications.

Demon, Brain, Soul

One popular modernization of Descartes is the 'brain in a vat' interpretation of his 'evil demon' scenario. He proposes the latter to explain the possibility that the existence of one's own body can be doubted--it might be an illusion produced by a evil demon. Analogously, a brain in a vat, located in a laboratory, could be stimulated to create the illusion of the possession of a body. Now, the evil demon scenario is a pivotal element in Descartes' attempt to prove the Immortality of the Soul, which entails the possibility that the Soul can survive the death of the Body. For, that the existence of the Body can be doubted, whereas that of the Mind cannot, provides Descartes with the decisive separation of the two. Perhaps the soundness of his argument is questionable, since it entails equating 'I am not certain of my corporeality' and 'I am certain of my incorporeality'. Regardless, the modernization undercuts Descartes' purpose--a brain in a vat is still corporeal--so that even if it does explain how the perception of one's own body is illusory, it falls short of accomplishing what Descartes requires at this juncture--the dubitably of any corporeality whatsoever. Such an abstraction from the importance to Descartes of the thesis of the Immortality of the Soul is not a isolated modern case. For example, Sartre seems to completely ignore it in his critique of 'I think, therefore I am'. Furthermore, arguments often known as 'Refutation of the Idealism', and 'Proof of the Existence of the External World', are ridiculed by Moore and Heidegger, without any evidence of recognition of the roles that they serve Kant in his argument against Descartes regarding the Immortality of the Soul. That Sartre--in-itself vs. for-itself; Moore--natural vs. non-natural; and Heidegger--beings vs. Beings, each inherit Cartesian dualism, is perhaps evidence of the shallowness of such presentations.

Descartes and Modern Philosophy

Descartes is often described as the 'father of Modern Philosophy', and the most frequently cited reason for that characterization is his principle 'I think, therefore I am'. But that proposition is hardly universally ascribed to by subsequent Philosophers, and, within his own project, is only one result of a more fundamental ambition. Indeed, what most of the main modern schools--Rationalism, Empiricism, Transcendentalism, Intuitionism, Phenomenalism, Phenomenology, Epiphenomenalism, Dialecticism, Structuralism, Deconstructionism, Analytic Logicism--share with Cartesianism is that they are methods in the quest for Certainty. Even one prominent seeming exception, Pragmaticism, is explicitly a method in pursuit of modified Certainty, i. e. highest Probability. So, Heidegger is mistaken to classify Descartes as a modern Protagoras, the father of modern Subjectivism. For Descartes does not assert that he is the measure of all things--his presumption is that his logically sound method of doubt is the measure of all things, including of 'I am'. Instead, Heidegger's own ontologization of Phenomenology only underscores that Descartes' primary influence on Modern Philosophy is as the progenitor of the ascendancy of Epistemology, a not necessarily intentional paternity.

Descartes, Circularity, Method

The 'Cartesian Circle' refers to the alleged circularity of the reasoning with which Descartes appears to argue both that he is certain that God exists because God exists, and that God exists because he is certain that God exists. However, if there is any circularity involved, it is not specific to the theological content of the argument; rather it is a characteristic of Cartesian methodology in general. His method entails three premises. First, every appearance A in consciousness has a cause X. Second, if an effect exists, then so too does its cause. Third, if it is impossible for A to have any other cause than X, then X is certain. So, if X is certain, it is the cause of A, and, therefore, it exists. Conversely, if X exists, and it causes A, then it is impossible that A have any other cause than X, and, thus, X is certain. So, the alleged Cartesian Circle entails a specific application of a methodology comprised of an Epistemological premise, an Ontological premise, and a Modal premise, respectively. Unfortunately, Descartes breeds confusion by often expressing the Modal proposition 'It is impossible to doubt X' in Epistemic terms, 'I am certain that X'. Hence, his 'I am certain that God exists', may, more properly, mean, 'God necessarily exists', which might defuse the charge of circularity.

Descartes, Doubting, Thinking

As has been previously discussed, Descartes finds Certainty in his uncertainty, i. e. he cannot doubt that he doubts. What rescues him from Skepticism is his further proposition that Doubting is Thinking. That proposition can mean one of two things: either that Doubting and Thinking are identical, or, that the former is a species of the latter. That he means that Doubting is a species of Thinking seems most likely, because to reduce other modes of Thinking to Doubting seems difficult. But, for that very reason, his inference from "'I doubt' is certain" to "'I think' is certain" is invalid, i. e. it entails an illegitimate generalization of a property of Doubting to all modes of Thinking. Now, such a clumsy introduction of Thinking into his argument may represent more than a relaxation of logical rigor. It encourages the suspicion that Descartes' primary aim is not a presupposition-less reconstruction of Knowledge, but a re-grounding of traditional soul-body dualism.

Descartes, Certainty, and Uncertainty

Often ignored in the attention to Cartesian doubt is the original problem that is its condition, i. e. the end to which Descartes designs it as a means, namely Certainty. The historical backdrop of Descartes' project is familiar--with the demise of Medieval Philosophy, perhaps prompted by the emergence of Copernican cosmology, Descartes seeks to rebuild Knowledge. Reconstruction requires a sound foundation, and Certainty is, for Descartes, the criterion of foundational stability. Abstractly, his plan seems reasonable, but, concretely, 'Certainty' is too vague to be accepted at face value. For, it is unclear whether Certainty is a state of affairs, or an attribute, and, if the latter, whether it is a subjective aspect of experience, or a property of an object of experience, and, in either case, whether it is part of sense experience or of intellectual experience. For example, 'S is certain that X' often refers to a feeling experienced by S, while 'X is certain' refers to a property of X. Now, Descartes seems aware that the subjective feeling of certainty is inadequate as a foundation, since its apparent solidity is fleeting. Hence, only intellectual certainty is acceptable, because only the intellect can make guarantees that transcend the moment. But, such certainty cannot be a subjective aspect of experience, which is in flux, so it must be a property of an object of experience. As it turns out, Descartes determines it to be a property of doubting, but not qua subjective experience, rather qua object of experience, i. e. of reflection. That is why Sartre is correct to note Descartes' equivocal treatment of doubting, i. e. it vacillates in his argument between subjective experience and object of experience. But, the equivocation is ultimately a function of the uncertainty of Certainty, which Descartes resolves by objectifying 'I doubt'. And, since, 'I doubt' is an expression of uncertainty, Cartesian Certainty, the foundation of his reconstruction of Knowledge, is his Uncertainty.

The Logic of 'I Can'

While Descartes focuses on the Logic of 'I doubt', his effort is complicated by his seeming unawareness of the complications of the Logic of 'I can doubt'. More precisely, it is the Logic of 'I can' that is the source of the complication. For, the semantics and truth conditions of 'I can X', i. e. what it means, and its relations to some state of affairs to which it presumably refers, seem to elude the operations of traditional declarative Logic. In some respects, the meaning of 'I can X' resembles that of 'A causes B', namely, that it often entails 'I have done X', with no new accomplishment sufficing to satisfy 'I can X'. But, even without skepticism about its causality, the performance of X only proves that 'I have X', or even 'I was able to X', but not 'I can X', even in an isolated case. For, say that the performance begins at t, and is complete at u--at t, 'I can X' has not been proven, and at u, only 'I was able to X' has been proven. In other words, even if one does perform X, there is no time at which 'I can X' is true. Falsification is no less unwieldy, though it does assist in better defining 'I can X'. At t, 'I cannot X' is indeterminate, nor does the failure at u do have performed X suffice to falsify 'I can X', but the latter does show that 'I can X' entails 'I attempt X'. So, 'I can X' seems definable as 'If I attempt X, I accomplish X'. Still, establishment of the truth conditions of the latter seems to remain difficult, since it entails accurately determining at what point effort qualifies as 'attempt', i. e. not trying hard enough does not mean not being able. So, independent of the Logic of doubting, the logical status of 'I cannot doubt that I can (or do) doubt' is problematic for Descartes.