In his Principles of Philosophy Descartes claims that the freedom of the will is one of the “common notions that are innate within us” and therefore does not need to be defended with argument. But as obvious as the notion of freedom of the will is the notion that God has pre-ordained all things, including our own actions. Descartes offers only our imperfect epistemic state as an attempt to reconcile these two incompatible truths. We are not in a position to understand how the two are compatible, but instead must simply assent to both propositions as known (CSM I 205-6). In his response to Hobbes' objections to the Meditations Descartes claims that the freedom of the will is “very evident by the natural light” (CSM II 133-4).
So Descartes will likely not be a place to find a full answer to the modern problem of free will and determinism, since he simply asserts compatibilism without arguing for it. But this idea that God causes everything is a form of determinism and it fits uncomfortably with the idea that we are responsible for our errors in judgment. So his versionof free will is in fact a version of compatibilism. Descartes also, despite his dualism, sought to provide an account of the relationship between the free mind and the deterministic world, of which the body is a part.
Showing posts with label Descartes. Show all posts
Showing posts with label Descartes. Show all posts
Friday, September 23, 2011
Thursday, May 26, 2011
You Die and then You're Dead and Here's an Equation to Prove It
Physicist Sean M. Carroll has a recent interesting post at the Scientific American arguing that what we know about the operations of our minds makes it extremely improbable that life after death is possible. His argument is a simple one: we know that mental faculties are the product of physical interactions in the brain, so my accepting the idea that some nonphysical thing (a soul) that is "me" in any relevant sense could outlast the demise of the body would require me to reject much of what we know about physics. Dualism is false and the proposition that the soul is immortal depends on dualism, so immortality is false.
Tuesday, April 19, 2011
Descartes' version of the Ontological Argument
For Descartes, anything that is perceived clearly and distinctly must be true. Therefore, when we know the essence of some idea, we have a clear and distinct idea of what that idea necessarily contains. In this ability to see as true or real any idea of a property contained in the essence of an idea Descartes sees another avenue for the demonstration of God’s existence.He claims to see clearly and distinctly that it is in the nature of God that he always exists. It is clear, he says, when he pays careful attention to the idea of God that God’s existence cannot be separated from his essence, any more than having three angles is separable from the idea of a triangle (CSM II 45-6). With this simple argument Descartes takes himself to have demonstrated the necessary existence of God.
Descartes anticipates an obvious objection: the fact that a property is part of the essence of an idea and cannot be separated from it doesn’t mean that entity that the idea represents actually exists. Descartes responds that because the property in question contained in the essence of God is his existence, it does in fact entail his real existence. It is not the thought or the definition that makes God necessary, rather it is his necessary existence that produces the necessity we clearly perceive in the idea of God. Descartes claims we are simply not free to think of God as not existing, for this would be to think of a supremely perfect being without a perfection (CSM II 46). He adds (without argument) that it is only in the case of God that existence is contained in the essence, so this argument could not be used to demonstrate the existence of anything else (CSM II 47).
One problem with this is the so-called "Cartesian Circle" in which Descartes may have employed a vicious circle in his defense of the veracity of clear and distinct ideas. According to some interpreters, Descartes needed the existence of God to provide the foundation for the reliability of clear and distinct ideas, which he then employed in his proof of the existence of God. Thus a vicious circle. This interpretation is contested, however (see here for more details). But even if we set that problem aside as unresolved there are major problems with this argument.
The notion that existence is a property contained in the essence of the idea of God is problematic. If Descartes means existence is a necessary condition (as part of a set of necessary and sufficient conditions) of being God, then the claim is uncontroversial but extremely uninformative. Also, the idea of God doesn't contain existence in any special way on this construal. In this sense existence is also a necessary condition of being a hammer (i.e., if something does not exist, then it isn't a hammer). But we can't infer anything at all about whether there actually are any hammers on the basis of this definition.
Alternatively Descartes could mean that there is a real metaphysical entity that is God's actual essence (like a Platonic form, perhaps), of which existence is a property in a way that existence is not a property of other real essences. Setting aside the profligate multiplication of entities this sort of metaphysics requires, Descartes gives us no reason for thinking that the essence of God is necessarily unique in this regard. Rather he repeatedly simply asserts that it is only the essence of the idea of God that has this necessary connection to existence; all other existences are contingent.
Ultimately, I think the only way to construe Descartes' argument without attributing a non sequitor to him is to read it as an argument for the psychological certainty that God exists. Unfortunately for Descartes, this means that he proves much less than he intended. The psychological version would go roughly like this:
The notion that existence is a property contained in the essence of the idea of God is problematic. If Descartes means existence is a necessary condition (as part of a set of necessary and sufficient conditions) of being God, then the claim is uncontroversial but extremely uninformative. Also, the idea of God doesn't contain existence in any special way on this construal. In this sense existence is also a necessary condition of being a hammer (i.e., if something does not exist, then it isn't a hammer). But we can't infer anything at all about whether there actually are any hammers on the basis of this definition.
Alternatively Descartes could mean that there is a real metaphysical entity that is God's actual essence (like a Platonic form, perhaps), of which existence is a property in a way that existence is not a property of other real essences. Setting aside the profligate multiplication of entities this sort of metaphysics requires, Descartes gives us no reason for thinking that the essence of God is necessarily unique in this regard. Rather he repeatedly simply asserts that it is only the essence of the idea of God that has this necessary connection to existence; all other existences are contingent.
Ultimately, I think the only way to construe Descartes' argument without attributing a non sequitor to him is to read it as an argument for the psychological certainty that God exists. Unfortunately for Descartes, this means that he proves much less than he intended. The psychological version would go roughly like this:
- We are psychologically unable to doubt the veracity of clear and distinct ideas
- We see clearly and distinctly that the essence of the idea of God contains existence as a property
- We are unable to doubt that God's existence is entailed by the idea of God
- We unable to doubt God exists
Thursday, April 7, 2011
Descartes' Argument from Personal Existence
Is it possible for me to exist if God does not? For Descartes, given that our existence is indubitable (I think, therefore I am), a negative answer to this question would serve as a demonstration that God's existence follows as a logical certainty from the indubitable proposition that I exist. In the Third Meditation Descartes seeks to establish the existence of God through just such an argument. He places the existence of God among three possible alternative causes for his existence: himself, his parents, or some other confluence of causes less perfect than God (CSM II 32-3).
Descartes surveys the other possible sources of his existence, dismissing each in turn.
First, if it were possible for him to bring himself into existence, then he should have given himself all the perfections he lacks, which would make him God. If he possessed the power of self-creation then he would possess enough power to give himself all other perfections. In addition, the power to create is the same as the power to sustain existence. Therefore, if he were self-created, then he would be responsible for maintaining his own existence. He does not do so, so he must not have been responsible for his own creation (CSM II 33-4). The key component of this portion of the argument is that Descartes is asserting that the power to create something is the same as the power to sustain the existence of something. There seems to be no reason to think that creative acts and sustaining acts--even those by God--are necessarily connected in the way Descartes supposes. Now, it seems fairly clear that I am not the source of my own being, even without Descartes' argument, but Descartes will deploy this notion of the equivalence of sustaining and creating later on in the argument.
Second, his parents cannot be considered to be the source of his being; they do not sustain him, and so insofar as he is a thinking thing, they did not make him, even if there is a sense in which they can be considered to be the source of his being in the world (CSM II 35). The dismissal of his parents as a legitimate explanation for his existence is based on the equivalence of creating and sustaining just mentioned as well as on Descartes' conception of the soul as thinking substance being somehow independent of the physical body. Descartes could accept a limited sense in which his parents brought him as a physical being into existence, but not that they are in any way responsible for the "thinking thing" that he identifies with himself. Cartesian dualism is implicit here, even though Descartes does not attempt to prove the thesis until later on in the Meditations.
Third, he cannot be the effect of a composition of causes because then he would have no source for the idea of God; the idea of God is a unity, and so cannot be a composite of other ideas (CSM II 34). This argument depends on Descartes' argument from conceptual content which I have discussed (and found wanting) previously.
First, if it were possible for him to bring himself into existence, then he should have given himself all the perfections he lacks, which would make him God. If he possessed the power of self-creation then he would possess enough power to give himself all other perfections. In addition, the power to create is the same as the power to sustain existence. Therefore, if he were self-created, then he would be responsible for maintaining his own existence. He does not do so, so he must not have been responsible for his own creation (CSM II 33-4). The key component of this portion of the argument is that Descartes is asserting that the power to create something is the same as the power to sustain the existence of something. There seems to be no reason to think that creative acts and sustaining acts--even those by God--are necessarily connected in the way Descartes supposes. Now, it seems fairly clear that I am not the source of my own being, even without Descartes' argument, but Descartes will deploy this notion of the equivalence of sustaining and creating later on in the argument.
Second, his parents cannot be considered to be the source of his being; they do not sustain him, and so insofar as he is a thinking thing, they did not make him, even if there is a sense in which they can be considered to be the source of his being in the world (CSM II 35). The dismissal of his parents as a legitimate explanation for his existence is based on the equivalence of creating and sustaining just mentioned as well as on Descartes' conception of the soul as thinking substance being somehow independent of the physical body. Descartes could accept a limited sense in which his parents brought him as a physical being into existence, but not that they are in any way responsible for the "thinking thing" that he identifies with himself. Cartesian dualism is implicit here, even though Descartes does not attempt to prove the thesis until later on in the Meditations.
Third, he cannot be the effect of a composition of causes because then he would have no source for the idea of God; the idea of God is a unity, and so cannot be a composite of other ideas (CSM II 34). This argument depends on Descartes' argument from conceptual content which I have discussed (and found wanting) previously.
Having dismissed three of the four alternatives in his quadrilemma, Descartes feels justified in taking this line of thought to have demonstrated the existence of God. Whether his argument really accomplishes what he thought it did is, as we've seen, debatable at best.
What is perhaps more interesting in all this is that Descartes felt that the fact of human existence was so mysterious a feature of the world that it required a special causal story to be told. If we reject dualism, then there is no reason to require any special explanation. If the mind is simply the loose moniker we give to the different capacities we have as the result of having big brains (rather than some extra thing that supervenes on the physical or is mysteriously associated with it somehow) then Descartes' problem dissolves to a large extent.
Human existence (including the existence of human intelligence) is a contingent fact about the world that is the result of a probably innumerable confluence of causes, any combination of which can be picked out depending on which aspect of human existence we find interesting. Answers to the question "why are we here?" could be explanations about what makes the universe in general or the earth in particular hospitable to life or about genetics and developmental biology or about human evolution or about human history or....
You get the point. There isn't any one answer for "why we're here," and Descartes' need to have one answer is derived from his insistence that there is something unnatural about our ability to think.
References:
Cottingham, J. G., Stoothoff, R., and Murdoch, D. (eds), The Philosophical Writings of Descartes, 2 vols. Cambridge University Press, 1985
What is perhaps more interesting in all this is that Descartes felt that the fact of human existence was so mysterious a feature of the world that it required a special causal story to be told. If we reject dualism, then there is no reason to require any special explanation. If the mind is simply the loose moniker we give to the different capacities we have as the result of having big brains (rather than some extra thing that supervenes on the physical or is mysteriously associated with it somehow) then Descartes' problem dissolves to a large extent.
Human existence (including the existence of human intelligence) is a contingent fact about the world that is the result of a probably innumerable confluence of causes, any combination of which can be picked out depending on which aspect of human existence we find interesting. Answers to the question "why are we here?" could be explanations about what makes the universe in general or the earth in particular hospitable to life or about genetics and developmental biology or about human evolution or about human history or....
You get the point. There isn't any one answer for "why we're here," and Descartes' need to have one answer is derived from his insistence that there is something unnatural about our ability to think.
References:
Cottingham, J. G., Stoothoff, R., and Murdoch, D. (eds), The Philosophical Writings of Descartes, 2 vols. Cambridge University Press, 1985
Friday, December 10, 2010
Descartes' Argument from Conceptual Content
Descartes offers three different arguments for the existence of God over the course of the Meditations. The first is an argument for the necessity of God's existence based on the nature of ideas and the content of our concept of God.
His demonstration of God’s existence begins with an analysis of ideas. According to Descartes, it is in the nature of ideas that they receive whatever "objective reality" they possess from something with as much or more objective reality. Descartes argument is this: if an idea contains something that is not in its cause, then it has come from nothing. But nothing comes from nothing. Therefore, the ideas I have cannot contain more perfection (or reality) than their causes. Descartes makes an analogy to pictures for support—a picture can fall short of perfect resemblance to its subject, but it makes no sense to claim that a picture exceeds the reality or perfection of that which it represents (CSM II 27-9).
What exactly he means by objective reality is a little difficult to pin down, and does not become significantly clearer even when he is pressed on the issue in the Objections and Replies that follow the Meditations. As far as I can tell, Descartes seems to subscribe to the notion that there are grades of being; substances have more reality than modes, for instance. This much was a fairly common notion at the time. But what I'm not sure was as common or uncontroversial is his claim that our ideas of substances have more reality than our ideas of modes, and this difference in reality is a causal consequence of the difference in reality of the entities the ideas represent. This undefended claim is necessary for his argument to get off the ground.
So Descartes concludes that any idea he has that has more objective perfection than he possesses cannot have originated within him. Ideas of material things contain nothing so great that they could not originate within him, however. Because so few of our ideas of corporeal things are perceived clearly and distinctly it is difficult for us to judge whether they are representations of real or unreal things, and so it is difficult to say whether they are the true cause of our ideas of them. Even those elements that are clearly and distinctly perceived in our ideas of objects could be supplied by our own minds (CSM II 29-31).
It is only when he comes to the idea of God that Descartes finds an idea that possesses a degree of objective perfection such that it couldn’t have come from within himself. All of the perfections of God that are present in objective reality within the idea of God must have been produced by a cause with as much perfection. It couldn’t be an extension of our idea of finite substance, because there is more reality in an idea of an infinite substance than in an idea of a finite one, and as finite substances we could not be the source of an idea of an infinite substance. Even though the idea we have of God is inadequate, the degree of perfection it possesses is sufficient for me to know I am not the source of it (CSM II 31-2).
There are several points at which this argument is problematic. First, it's not at all clear that even if there exist degrees of reality in the world that this continuum of existence is reflected in our thoughts. What reason do we have for saying that our idea of a unicorn is less real than our idea of a horse? Clearly a horse is real and a unicorn is not, but what sense does it make to say that the ideas we have of them possess different levels of reality? Descartes simply stipulates this continuum of ideas and doesn't offer us any reason why we should accept it.
Second, even if we grant that ideas do display this continuum of being, there is no indication that this variability in reality is isomorphic with the variability of the reality of the entities the ideas represent. He argues only that there must be some cause of the contents of our ideas, but the move to the notion that the objective reality of the contents of our concepts parallels the objective reality of their objects is a sleight of hand. It's certainly conceivable that the contents of our ideas (and thus the differing objective reality) could have come from some other cause than the object they represent.
These two considerations are sufficient to block the argument, but I also want to look more closely at his contention that the idea of God is something that couldn't be a human construction, because this notion recurs in theological arguments from time to time in one form or another. Descartes bases his claim that our idea of God cannot be a construction on the claim that the idea of an infinite substance cannot be an extension of our idea of finite substance; that is, there is no mental operation available to us to build an idea of infinite substance from our ideas of finite substances. In reality however, it seems eminently plausible that just such an operation is available to us.
Take as an example the idea of numerical infinity; we certainly don't have an idea of numerical infinity on the basis of having ever experienced infinite numbers, but we can construct an idea of numerical infinity by repeating a mathematical operation on a number (addition) and recognizing that there is, in principle, no limitation on applying indefinitely. One plus one is two, plus one is three, plus one is four, and so on. We can have an idea that there is no upper limit on numbers because we see that addition can continue indefinitely.
Why couldn't the infinite properties of God be constructions in exactly this way? Our idea of his infinite goodness can be an extension of the notions of goodness we have from our experiences in the world. Similarly with all the other properties of God; the infinity, power, knowledge etc. that we attribute to him could simply be exaggerations of things we experience in the world. Descartes admitted that the idea of God we have is inadequate but claimed that degree perfection they possess shows that cannot be human construction. This however, does not seem to be the case.
Cottingham, J. G., Stoothoff, R., and Murdoch, D. (eds), The Philosophical Writings of Descartes, 2 vols. Cambridge University Press, 1985.
His demonstration of God’s existence begins with an analysis of ideas. According to Descartes, it is in the nature of ideas that they receive whatever "objective reality" they possess from something with as much or more objective reality. Descartes argument is this: if an idea contains something that is not in its cause, then it has come from nothing. But nothing comes from nothing. Therefore, the ideas I have cannot contain more perfection (or reality) than their causes. Descartes makes an analogy to pictures for support—a picture can fall short of perfect resemblance to its subject, but it makes no sense to claim that a picture exceeds the reality or perfection of that which it represents (CSM II 27-9).
What exactly he means by objective reality is a little difficult to pin down, and does not become significantly clearer even when he is pressed on the issue in the Objections and Replies that follow the Meditations. As far as I can tell, Descartes seems to subscribe to the notion that there are grades of being; substances have more reality than modes, for instance. This much was a fairly common notion at the time. But what I'm not sure was as common or uncontroversial is his claim that our ideas of substances have more reality than our ideas of modes, and this difference in reality is a causal consequence of the difference in reality of the entities the ideas represent. This undefended claim is necessary for his argument to get off the ground.
So Descartes concludes that any idea he has that has more objective perfection than he possesses cannot have originated within him. Ideas of material things contain nothing so great that they could not originate within him, however. Because so few of our ideas of corporeal things are perceived clearly and distinctly it is difficult for us to judge whether they are representations of real or unreal things, and so it is difficult to say whether they are the true cause of our ideas of them. Even those elements that are clearly and distinctly perceived in our ideas of objects could be supplied by our own minds (CSM II 29-31).
It is only when he comes to the idea of God that Descartes finds an idea that possesses a degree of objective perfection such that it couldn’t have come from within himself. All of the perfections of God that are present in objective reality within the idea of God must have been produced by a cause with as much perfection. It couldn’t be an extension of our idea of finite substance, because there is more reality in an idea of an infinite substance than in an idea of a finite one, and as finite substances we could not be the source of an idea of an infinite substance. Even though the idea we have of God is inadequate, the degree of perfection it possesses is sufficient for me to know I am not the source of it (CSM II 31-2).
There are several points at which this argument is problematic. First, it's not at all clear that even if there exist degrees of reality in the world that this continuum of existence is reflected in our thoughts. What reason do we have for saying that our idea of a unicorn is less real than our idea of a horse? Clearly a horse is real and a unicorn is not, but what sense does it make to say that the ideas we have of them possess different levels of reality? Descartes simply stipulates this continuum of ideas and doesn't offer us any reason why we should accept it.
Second, even if we grant that ideas do display this continuum of being, there is no indication that this variability in reality is isomorphic with the variability of the reality of the entities the ideas represent. He argues only that there must be some cause of the contents of our ideas, but the move to the notion that the objective reality of the contents of our concepts parallels the objective reality of their objects is a sleight of hand. It's certainly conceivable that the contents of our ideas (and thus the differing objective reality) could have come from some other cause than the object they represent.
These two considerations are sufficient to block the argument, but I also want to look more closely at his contention that the idea of God is something that couldn't be a human construction, because this notion recurs in theological arguments from time to time in one form or another. Descartes bases his claim that our idea of God cannot be a construction on the claim that the idea of an infinite substance cannot be an extension of our idea of finite substance; that is, there is no mental operation available to us to build an idea of infinite substance from our ideas of finite substances. In reality however, it seems eminently plausible that just such an operation is available to us.
Take as an example the idea of numerical infinity; we certainly don't have an idea of numerical infinity on the basis of having ever experienced infinite numbers, but we can construct an idea of numerical infinity by repeating a mathematical operation on a number (addition) and recognizing that there is, in principle, no limitation on applying indefinitely. One plus one is two, plus one is three, plus one is four, and so on. We can have an idea that there is no upper limit on numbers because we see that addition can continue indefinitely.
Why couldn't the infinite properties of God be constructions in exactly this way? Our idea of his infinite goodness can be an extension of the notions of goodness we have from our experiences in the world. Similarly with all the other properties of God; the infinity, power, knowledge etc. that we attribute to him could simply be exaggerations of things we experience in the world. Descartes admitted that the idea of God we have is inadequate but claimed that degree perfection they possess shows that cannot be human construction. This however, does not seem to be the case.
Cottingham, J. G., Stoothoff, R., and Murdoch, D. (eds), The Philosophical Writings of Descartes, 2 vols. Cambridge University Press, 1985.
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