ISBN: 9780195075908

READ: 2016-12-04

Author: Georges Dicker



Meditation I : The Method of Doubt

As an introduction, we should note that Descartes embarks in the challenge of doubting everything with a purpose: to discover if there may be some certainty to build upon, with the same method you would use to inspect a basket of apples and separate rotten ones from the unspoiled.

Can we say that if one ventures to find some principles, especially when there is no empirical data to confront them against with as it is the case of Descartes in his Meditation I, the purpose attached to that research is what will define the outcome? By doubting everything, Descartes emerges in the end with a strong, true principle; sceptics don’t.

By the time Descartes undertook his philosophical quest, the scientific revolution of the 17th century had already wiped out the teleological view of nature, and the universe became to be conceived as a great machine. The true novelty with respect to the Medieval Ages is that there is no place for purpose in the universe anymore. (p.6)


After analysing the first meditation, Dicker proceeds to investigate whether the three main sceptical arguments – the Deceptiveness of the Senses, the Dreamer Argument and the Deceiver Argument – are self-defeating, an issue into which sceptics can run.

The first is dismissed as non self-defeating, for Descartes argues that senses should not be trusted completely, not that they shouldn’t be trusted at all. Therefore, he can affirm that because senses are sometimes deceptive, they should not be entirely trusted.

The second argument is in fact self-defeating: how could Descartes tell whether his dream perceptions and wake perceptions have the same vividness, without him actually knowing what the difference is between dreams and wakefulness? Dicker concedes although that for the sake of Descartes’ argument, one does not need to be certain of the difference between the two states to suspend judgement about the issue: having a belief about that is sufficient.

With concern to the third argument, Dicker points out that while the conclusion is that all senses provide no certainty, the premiss is an analytical (= a priori) argument; therefore, the Deceiver Argument doesn’t imply any contradiction.

An analytical argument is what can be known to be true just by thinking – given, of course, that words need first to be learned through experience. Once words are learned, anyway, analytical statements are true by definition, i.e. do not need any empirical (a posteriori) evidence to be confirmed. The underlying conceptual frame of Descartes’ Deceiving Argument is, according to the author, the causal conception of perception (CCP):

For any person S and material object M, S perceives M at time t only if M is a cause of S’s perceptual experience at t. (p.30)


How does one show that this statement is analytical and true?

Dicker’s demonstration:

  1. take a contradictory statement: “I see a pen, but it is not the case that a pen is one of the causes of my perceptual experience.”
  • negate the contradiction, making it thus an analytical statement:
  1. “If I see a pen, then a pen is a cause of my present visual experience”
  • Logical proof of the negation: 1. has the form p and not-q, its negation is not(p and not-q) -> if p, then q:
  1. “I see a pen only if a pen is a cause of my present visual experience”
  • where 2. form if p, then q has been translated into p only if q

Note that analiticity is hereditary, from 1. to 3. (see p.32-33)



Meditation II : The Cogito and the Self

Descartes can summarise that he exists because even though he doubted that he could exist, the very fact of doubting proves that he exists as a ‘thinking thing’. He tests the cogito against the Deceiving Argument and finds out that if a demon were deceiving him, Descartes would need to exist anyway to be deceived.

Note that the latin cogito, ergo sum wants to express is sense of continuity, that is that until I’m engaged in the process of thinking, I exist;

I am thinking, therefore I exist

Descartes employs here a positive doctrine: that all reflexive judgements (or subjective meta-thoughts: beliefs about one own’s thoughts) should be true.


One may ask why couldn’t Descartes carry out his skepticism through the assumption that he might be insane. It is although legitimate to dismiss that option, for a person that considers himself to be insane cannot pretend to discover any truth by means of philosophical reasoning; it is therefore possible to reject all possible instances of confuse perception that may have let Descartes think he had two opposing beliefs about what he perceived (example from Dicker: “a person who thought he believed he saw a horse while really disbelieving this”, p.48 – what contemporary philosophers would classify as a type of “Moore paradox”), for they would make the case of an insane subject.


A basic problem with the cogito: “What entitles Descartes to use the first-person pronoun “I” in the premiss of his proof?” (p.48), i.e. that “I” am thinking?

  • in this form, the proof of existence is question-begging;
  • following Russell’s interpretation of “I” as simply of grammatical convenience, we would derive the proof “There is a thought, therefore I exist”, which is invalid;
  • Jaakko Hintikka1) proposed to view the cogito as a performance, that the very fact of questioning one’s existence makes it evident of one’s existence beyond any argument; this interpretation has been criticised as too narrow (the proof of existence would rely on the specific thought of doubting one’s existence, but Descartes wanted the whole thinking experience to be such a proof) and it should be supported by an argument anyway to justify why specifically that procedure would guarantee the existence proof.
Dicker turns therefore to explain the main assumption underlying the cogito: the substance theory. Substance theory, in opposition to the bundle theory, asserts that a thing is a collection of properties plus an underlying, ‘reference’ substance. The substance theory is supported against the bundle theory from the Argument from Change – that “A human mind is a substance, since even if all its determinate properties change, it is still the same mind.” (p.53)

Once this basic assumption has been recognised, and once we acknowledge that Descartes assumes that a substance cannot exist without properties, and viceversa, the cartesian thought would naturally be considered a property of an underlying substance, namely the ego: “He knows what a thought is, he knows that it is an attribute and not a substance. Again, by the light of nature, he knows that every such attribute must belong to a substance. Se ho concludes to the existence of the substance of which the thought he perceives is an attribute, This he calls ego; or, if you like, he concludes that the “I” in “I am thinking” does refer to a substance and is not just a grammatical convenience.” (Anthony Kenny, quoted in Dicker at p.56)


Critical points with the Substance Theory:

Substance is ‘unperceivable in principle’, therefore many empiricists reject it; that is not enough, for one needs to reject the underlying Argument for Change, not such an easy task. Dicker mentions contemporary attempts inspired by Locke’s work to defeat the Argument, by appealing to the concept of “spatio-temporal continuity”.


Critical points with the “substance-property principle”

It is not obvious that properties must depend on a substance in order to exist. The issue here points to the controversial problem of universals. The three main competing theories in that field are Platonic Realism, Moderate Realism (born with Aristotle; what Descartes takes as the assumption) and Nominalism (supported by the English empiricists). Needless to say, each of them face some difficulties.

One more assumption that Descartes did not acknowledge: that thoughts must be properties, rather than substances – something he takes for granted and does not proceed to demonstrate.

What Descartes cannot do, anyway, is to assign the existing thing which has just been derived from the aforementioned premisses to the pronoun “I”: we may grant that the thinking thing exists, but there is are no grounds by which we could say that this substance is someone – not myself more than you, or the platonic world-soul. To recap: from “I am thinking” does not follow that “I exist”.

Here I found helpful to quote at full length the following philosophical proof:

“it is impossible to prove one’s own existence. If this is correct, then Descartes’s error was not that he held that “I exist” is certain – on that point he was surely right – but that he held that “I exist” can be proved from “I am thinking”.” (p.63)


Dicker makes explicit Descartes’s parallel between the concept of a material thing – the example of the wax, which bears the same concept in face of its changing properties – and the thinking substance – again, the substrate of changing cogitationes, thoughts. This lays the foundations of Cartesian Dualism: a thinking unextended substance (res cogitans) and an extended, unthinking one (res extensa).

By the end of Meditation II, Descartes gets to the point where he can be sure to know only that he is a thinking thing, but he does not exclude the possibility of being a body, something that he will try to demonstrate in Meditation IV; Cartesian Dualism has therefore not being established yet – we only have a hint to it.



Meditation III : The Existence of God and the Criterion of Truth

Derivation of the criterion of truth from the cogito:

“If something could be clearly and distinctly perceived yet false, then this would shed doubt on the cogito itself. But the cogito is absolutely indubitable. Therefore, what is clearly and distinctly perceived cannot be false; so it must be true.” (p.84)

We must here further remember that the cogito is a complex structure, composed by “I am thinking”, “‘I am thinking’ entails ‘I exist’” and “I exist”. “I am thinking”, as we have seen is certain; the second is certain because the entailment is obvious; “I exist” is certain because it follows from two certain propositions. The criterion of truth will be used by Descartes to establish the existence of God, mind-body dualism and the existence of a material world.

Descartes can be absolutely certain of the clearness and distinctiveness of his perception while he is focused on that perception, but he still doubts whether the very fact of perceiving something clearly and distinctly can be taken as a criterion of truth. Thus, he addresses the issue of God: he must show that he exists, and that he does not deceive.


Introducing the Cosmological Argument for the Existence of God

For Descartes, God is the ultimate, necessary cause of the effects we experience; here effects cannot be physical, for the existence of a physical world has not been postulated yet: Descartes thus grounds his argument upon the fact that his idea of God must have its cause in God himself.

For Descartes, an idea is something that must exist; it is like a picture of something, it has a thing as an object, but is nor true nor false, since the idea simply exists. Truth and falseness are only coupled with judgements or inferences about ideas. In considering ideas as pictures, Descartes differentiates their status between ‘more objective’ – ideas that represent a substance – and ‘less objective’ – those which picture a property; more specifically, the degree of reality of different ideas matches the degree of reality of their objects if they would exist. At the same time, ideas can be said to have the same ontological footing, when considered as ‘modes of thinking’ – states of mind that come and go.

We are proceeding to lay down what Dicker calls “the core argument”, the proof of God’s existence. We should now add another useful tool to fully understand the coming argument, which is that Descartes employs the principle by which something cannot proceed from a cause that is less real than its effect. Descartes will may his point clearer in the Principles of Philosophy (part 1, no.17) by making the example of a complex machine, which cannot be more complex than the man who designed it.2)The idea that the Universe must have a cause, by taking the existence of complex objects as a proof of the existence of God, will be challenged by Darwinians; the most recent and popular example has been given in The Blind Watchmaker, by biologist R. Dawkins. The scholastic rule that “everything must have a cause” is justified by Descartes with the Latin Ex nihilo, nihil fit.

Moreover, note that modes of thought have a lower degree of realty than a finite substance, and the latter has a lower degree of reality than an infinite substance. All things being thus considered, the core argument could be presented as follows:

  1. “The cause of an idea must have as much reality as the idea represents its object as having.
  2. Only a perfect God has as much reality as my idea of God represents him as having.
  3. The cause of my idea of God is a perfect God (from propositions 1 and 2)
  4. A perfect God really exists.” (p.99)
An interesting point here is that by assuming the existence of a necessary formal cause to the idea of God, and by recognising that Descartes himself could not be that cause, for he does not have nor a superior nor an equal reality status than the idea of God has, Descartes postulates that there must be something else outside him, thus ending his solipsism.

Let’s not forget that the core argument has been brought about to support the criterion of truth. Once the existence of God has been established, and because God is by definition a perfect being, since deceiving would be an imperfection, God cannot be a deceiver. Therefore, every clear and distinct perception, as it is caused by God, must be true.


Critical points: the ‘precontainment argument’

As Hume clearly pointed out, even upon scrupulous inquiry, it is impossible to recognise an effect within its cause, as they must be separate; the Humean theory of causality says that cause and effect are events, which possess a distinctiveness that could hardly be accounted for if the effect was somehow contained in the cause. Dicker, however, proposes to take the Cartesian version of causality not so strictly, rather to consider it more commonsensically: that “the cause must precontain the reality of the effect” (p.112). Such doctrine is quite problematic anyway, as any evolutionary biologist would tell you. The last possible proposed interpretation was given by Mackie – that Cartesian causality can be considered as a sort of conservation principle; the point here is that scientific conservation principles stem from inference, and could therefore not be used by Descartes in a context where external reality hasn’t been proved yet.


Critical points: degrees of reality

Hobbes was the first to ask for a grounding explanation to the doctrine of degrees of reality. Descartes continued to consider it ‘self-evident’, and the only thing we can be certain about is that God, in Descartes’s mind, has a higher degree of reality because he can exist without substances, while the opposite cannot be true. The same strategy, though, does not work on a substance-property scale, for although properties cannot be “free-floating”, it is also true that there cannot be a substance without properties; to infer that properties have a lower degree of reality than substances from the fact that properties change while substances don’t is an altogether different criterion than the previously employed dependence-independence rule, and the doctrine is therefore not much coherent.


Critical points: the causation theory

Criticism toward the Ex nihilo, nihil fit maxim also has a Humean taste: the proposition bears a double meaning, namely that

  • Nothingness cannot be a cause
  • Something cannot exist without a cause

From the argument for which “Nothingness cannot be a cause” we cannot logically deduce, as Descartes does, that “Everything must have a cause”; at the same time, if from the “Something cannot exist without a cause” point it follows that everything must have a cause, that argument is not supported by the first premiss, i.e. that “a cause must precontain the reality of its effect”.

To recap:
  • “A cause must precontain the reality of its effect” -> (valid) “Nothingness cannot be a cause” -> (invalid) “Everything must have a cause”
  • “A cause must precontain the reality of its effect” -> (invalid) “Nothingness cannot be a cause” -> (valid) “Everything must have a cause”

What Dicker offers here to defend Descartes is a quote by E. M. Curley, an explicit challenge to Hume: “Admittedly I can conceive of something springing into existence ex nihilo. But I cannot believe that this ever happens.” (p.118) Thus, from a logical standpoint, the argument is far from being solid; it nevertheless stands upon strong sense of what ought to be believed.


Critical points: the Cartesian Circle

Arnould moved the following criticism in the Objections to the Meditations: that Descartes proves the existence of a non-deceiving God through the reliability of clear and distinct perception, and at the same time holds that clear and distinct perceptions are reliable because they are given by God.

A possible answer depends upon whether we could show that either clear and distinct perception either the existence of God can be established before the other.

In the analysis of what Dicker calls “The vindication-not-needed strategy”, namely that God is not necessary to insure the truth of clear and distinct perception, it emerges the renown argument by which Descartes would call God’s existence only to warrant that one’s memory of clear and distinct perceptions are not deceivable. The author presents a set of different philosophical and philological arguments to claim that the memory defence is not one of Descartes; the interpretation which has been put forward (by scholar James Van Cleve3) is that Descartes would use the divine guarantee to get from the memory of a clear and distinct perception to the claim that it must be true – not to confirm the reliability of one’s memory, rather to support that that memory is in fact true. Thus, Descartes would not escape the guilt of circularity.


Trying to escape the Cartesian Circle

The most relevant justification for Descartes’s independence of clear and distinct of perception lies in the so-called “General rule defence”, by which some scholars argue that God is required to warrant that clear and distinct perceptions are true in general, but that there are particular perceptions, as Descartes repeatedly points out, that cannot possibly be false – statements as “I am thinking, therefore I exist” or “2+3=5” are ‘assent-compelling’.

Dicker’s thesis is that the general rule is self-defeating: if the general principle of clear and distinct perception cannot be certain before the proof of God’s existence, then that very doubt must contain the proposition that even while having a clear and distinct perception one may be wrong. “Doubting the general principle must consist in thinking ‘Even when I was having a clear and distinct perception, which admittedly I could not doubt at the time I was having it, I may nevertheless have been mistaken: the proposition that I was then clearly and distinctively perceiving may actually have been false.’” (p.131)

How could then Descartes’s position be saved? If the Cartesian doubt stems from reasons that brought him to think that there may exist an omnipotent God, who can do anything and therefore may even deceive him altogether, reason itself can, upon further inquiry, provide a basis to nullify that doubt. The initial doubt would therefore be a prima facie, and will be defeated by building through reasoning the theological argument, namely that an omnipotent God, even though can be conceived as deceitful, must reasonably be non-deceiving because of his perfection.

This point tackles the problem of radical skepticism so deeply, that I want to quote Dicker at full length on the issue: “Once we grant the legitimacy of the use of reason required to infer the possibility of our going wrong about the simplest things from the possibility that there is an omnipotent God, there is no reason in principle to deny the legitimacy of the use of reason that leads to the conclusione that the omnipotent God who actually exists is a perfect being who, while still fully able to deceive his creatures, would not wish to do so. Indeed, consistency requires that if we allow the former use of reason to be legittimate, then we must also allow the latter to be legitimate.” (p.139-140) Thus clear and distinct perceptions “are used only because they constitute the most careful use of the intellect we are capable of” (p.140): the theological argument is completed successfully and validated in absence of reasons for doubting, and it simultaneously validates reason itself.


The theological argument has become so significant, that we have to examine whether Descartes can really prove that such an omnipotent and infinite God exists. His response to Gassendi’s criticism is that men can understand the nature of God without necessarily grasping it, that is sufficient to be able to ‘touch’ it rather than ‘embrace’ it in order to know that he is omnipotent, benevolent and infinite. Bernard Williams4) has put forward a powerful charge: to be able to conceive that such God exists, without being able to explain how come he is so infinite etc., does not guarantee that he should be the equally-powerful formal cause of Descartes’s idea of God.



Meditation V : The Ontological Argument for the Existence of God

There is still another proof in Descartes’s toolkit for the existence of God, that is the Ontological Argument. It combines the criterion of truth and the connection between supreme perfection and existence to postulate that a supremely perfect being, i.e. God, must exist. The heart of the argument, anyway, lays in the assertion that existence is a perfection: a supremely perfect being, who cannot lack any perfection, should therefore exist.

The most powerful objection to the Ontological Argument has been stated by Kant: following his reasoning, by posing that existence is not a property as Descartes wants it to be, that existence is a perfection should consequently be rejected. Kant’s argument is that existence cannot be considered as a ‘descriptive property’, rather as a concept that is applied to something. For example, if we say that “zebras are striped”, striped assigns a particular property to its subject. By asserting that “Zebras exist” instead, we are simply stating that the term “zebras” applies to something.

However, Kant’s objection is considered to be not conclusive. Some have argued that existence can be regarded as a property of things we know exist, just as non-existence could be thought of as a property of dragons, gremlins and unicorns. Dicker reinforces Kant’s argument with Deflationism, a popular solution to the problem of negative existentials, i.e. statements like “Carnivorous cows do not exist”. Deflationism holds that negative existentials are not about their subjects, rather that the concept of a carnivorous cow is not exemplified; such statements should be considered as deceptive due to their grammatical appearance. By embracing the necessary isomorphic application of deflationism to affirmative existentials, one would strongly be committed to the Kantian objection that existence is not a descriptive property, for “a carnivorous cow” would then be non-existent because its concept is nowhere to be exemplified. Nevertheless, negative existentials such as “Dragons do not exist” are much more difficult to deal with, hence also the deflationist argument is not conclusive of Kant’s objection.


A further complication: Material Mode of Speech and Formal Mode of Speech

The core of another renown objection, moved by priest Catarus in the first set of Objections to Meditations, is that one cannot transpose the conceptual into material existence. The issue has been clarified further in the last century, when philosophers began to adopt two ways of talking about words: Material Mode of Speech (MMS) and Formal Mode of Speech (FMS), that is words which respectively refer to nonconceptual realities and definitions or concepts.

By applying such distinction to Descartes’s argument

  1. A supremely perfect being has all perfections
  2. Existence is a perfection
  3. Therefore, A supremely perfect being exists

and being n.1 clearly a definition, i.e. a formal mode of speech, the argument is invalid: From two formal modes of speech Descartes derives a material mode, that is the existence of something.


Final remarks

All things being considered from the analysis of both Meditation III and V, it emerges that Descartes has failed to carry out his theological argument. The criterion of truth should thus not be considered as guaranteed by the existence of God, rather to stand on its own. Everything that lies outside the criterion of truth, such as dualism, should therefore be considered as baseless, for it depended on the reliability of the theological argument.



Meditation VI : Dualism and the Material World

Upon the criterion of truth, Descartes builds the argument that since being able to clearly think of two entities X and Y makes them possible to exist separately, at least by God’s power, and since he can perceive his mind as independent from the body, then mind and body could exist separately. It follows that immortality is not proved as necessary, rather as merely possible.

Yet, how come, as Arnauld puts it, that if I can conceive of a triangle without thinking about his Pythagorean property, I necessarily cannot deceive myself while clearly perceiving myself as a thinking thing without extension? Descartes’s answer is that just as it is possible to conceive of a triangle without considering his Pythagorean property, but it is impossible to think of a triangle while holding at the same time that it does not have such a property; so it must also be true that if I can conceive myself as a thinking thing, it necessarily follows that I am an unextended substance, as it has been show in Meditation II.


The basis for the existence of the Material World is drawn directly from the thesis that there is a perfect God and that he cannot possibly deceive us; the whole argument is therefore unsuccessful, as we have previously seen from Meditations II and V. Dicker argues therefore that Descartes has not secured any certain knowledge besides the radical skepticism of the cogito of Meditation I.

Anyway, we shall know briefly outline what his general argument about the existence of external bodies is. First of all, since Descartes has sensory experiences, for the same principle followed in Meditation III, they must have a cause that has at least the same formal realty as the objective reality of those very perceptions. And since Descartes asserts that he cannot possibly be the cause of those perceptions, as they arise independently of his will, then perceptions’ causes must rely outside of him. How does then Descartes prove that those perceptions are not caused by God or by some other nonphysical identities, in other words something other than physical bodies?

“The cause of my sensory experiences cannot be God or any created substance other than bodies; for God has given me no way to spot that this is so but, instead, a very powerful inclination to believe that the experiences come from bodies (material objects). So God would be a deceiver if the experiences were produced in any other way. But since God is s supremely perfect being, he cannot be a deceiver.

Therefore, bodies exist.” (p.202)

Descartes subsequently establishes the existence of an extended substance (space-matter, the renown res extensa), of which bodies are properties, accidents.


The mind-body problem: Interactionism and proximate causation

Descartes repeatedly states that he can know that his mind has a special relationship with his body; specifically, he points to the pineal gland as the physical place within the brain where the interaction between the unextended substance (mind) and the extended one (body) would occur. The major problem with dualism as always been that of explaining how could an unextended and an extended property possibly interact: there cannot be any physical, mechanical, thermal event that could pass a bodily sensation to the mind, and the reverse is just as impossible.

Here it is proposed a recent development of the interactionist theory by Ducasse, who raises the notion of proximate causation to make dualism more plausible. Proximate causation is a definition of any cause-effect relationship of which no intermediary steps are identifiable to explain how the causation process works: if, for example, a specific mental event causes particular electrical level in some synapsis, there really is nothing more to it to explain precisely how that happens – it is a brute fact. Now, brute facts can be thought of ‘regularities’ – in a Humean way, we assess that in nature to some events necessarily follow other specific ones, and such occurrences cannot be further warranted other than by appealing to even more general regularities. All things being considered, mind-body interactions such as the synapsis example described above can be described as regularities – as brute facts which have no less legitimacy than monistic accounts of philosophy of mind.


The mind-body problem: Cartesian Dualism’s reliability

Dualism has foregone a substantial rebuttal since the advance of materialism; the author here courageously proceeds to examine whether its debacle is definitive or not: maybe Dualism stil has something to tell us. The most recent dualist version he put forward is that of Cornman; according to him, mental events can be thought to be causing neural impulses together with brain events, with the concession that mental events depend on brain stimuli themselves. Mental events would thus be irreducible to physical occurrences. Dicker argues that the Ockham Razor is not relevant, for the it should be applied to entities that hold a primary explanatory power, of which there is no independent evidence. Mental events, on the other hand, are to him not essential to explain how neural impulses occur (for they could be detected directly form the ultimate cause of brain events) and are supported by independent evidence, namely that of introspection and that of the logical conclusion that since we can conceive of the mind existing independently of the body, it follows that the mind can exist without the body and so that body and mind must differ from one another. 5)A thorough analysis of the mind-body problem with respect to the issue of consciousness can be found here: Explaining Consciousness. With respect to some methodological issues within philosophy of science, a review of Sober’s recent work Ockham’s Razors will soon be released.

In defence of Descartes’s account of a weaker dualism, I’d quote Dicker as a closing remark:

Nothing in Descartes’s case for dualism rules out such dependence of res cogitans on res extensa. At best Descartes’s arguments give a certain epistemological priority to res cogitans – show that its existence can be known before that of res extensa. But this does not mean that res cogitans has any metaphysical priority – that it can actually exist independently of  res extensa. (p.231)


References   [ + ]

2. The idea that the Universe must have a cause, by taking the existence of complex objects as a proof of the existence of God, will be challenged by Darwinians; the most recent and popular example has been given in The Blind Watchmaker, by biologist R. Dawkins.
5. A thorough analysis of the mind-body problem with respect to the issue of consciousness can be found here: Explaining Consciousness. With respect to some methodological issues within philosophy of science, a review of Sober’s recent work Ockham’s Razors will soon be released.