Jay Dyer, TAG, and Modern Philosophy

 The Transcendental Argument for God (TAG) is a modern argument for the existence of God popularly supported by Jay Dyer online. TAG differs from more well-known arguments like the Cosmological Argument in taking what might be called a "meta" perspective. It argues from the possibility of argument itself to the existence of God.

Listening to Dyer discuss TAG on his YouTube videos, he uses words like "paradigm", "presuppositions", "assumptions", and "worldview" frequently.  This is an indication that TAG is a characteristically modern argument, as opposed to something like Aquinas's Five Ways, which are characteristically classical. To understand what is really going on in TAG,  we must first understand some distinctive features of modern philosophy.

Rene Descartes may be, and often is, designated as a convenient dividing line between ancient and modern philosophy. It is not just when he lived that makes this natural (1596-1650), but also the manner in which he approached philosophy. As a young man, Descartes concluded that what he had learned in school - specifically, philosophy in the Scholastic tradition - produced nothing that was not doubtful and uncertain. He resolved to reject that tradition and replace it with a system he believed would produce certainty. This system was his famous method of methodical doubt, which would subject everything to the most searching doubt and accept only that which might survive. The first result of this method was his famous cogito ergo sum - I think therefore I am.

Subsequent philosophers were deeply influenced by Descartes, but not quite in the way he hoped. Descartes thought he had restarted philosophy once and for all on a sure footing and later philosophers would follow his method and expand its results. While those later philosophers agreed with Descartes that the classical dialog of opinion merely resulted in fruitless debate, the lesson they took from Descartes was that they could restart philosophy themselves on whatever grounds seemed reasonable to them. It was not illogical for them to think so. A consequence of Descartes' approach was to divide thought into two realms: The realm based on methodical doubt that produced reliable and certain results, and the realm of thought not founded on that method and therefore capable only of producing uncertain and doubtful results. The thinking of Descartes before he restarted thought with his method of doubt - the time when he concluded that the Scholastic tradition was barren and in which the method of doubt itself was selected - necessarily occurred in that second realm of doubt and uncertainty, the "gray zone" of thought as it were, since it occurred before the invention of methodical doubt. Since by its own lights it was doubtful and uncertain, philosophers were happy to doubt it and felt free to select their own methods on which to reconstruct philosophy.

What followed was, among others, John Locke starting philosophy with his "plain, historical method",  David Hume researching the "secret springs and principles, by which the human mind is actuated in its operations" and, most comprehensively, Immanuel Kant defining the categories of human thought in his Critique of Pure Reason.  Things proceeded in a similar manner from there, and the long term consequence of Descartes' philosophical revolution is the general conviction that philosophy begins more or less arbitrarily from some set of first principles that cannot themselves be rationally demonstrated. Everyone is free to choose from where he will begin.

This results in philosophical discourse about "worldviews", "presuppositions" and "paradigms." A worldview is your comprehensive view of things that results from the logical development of your presuppositions. Your paradigm is the methodical framework within which your worldview is explored. Since everyone's worldview is constructed from presuppositions that can be neither defended nor refuted, and not everyone's presuppositions are the same, philosophical debate is only possible where the participants can agree on some set of presuppositions from which valid argument can proceed. If agreement cannot be reached, then fruitful debate is not possible. So debates, including debates concerning the existence of God, often start with a preliminary discussion over what set of presuppositions can be agreed on.

This standard procedure TAG claims to transcend by arguing at a "meta" level.  The argument is about the presuppositions themselves rather than some set of conclusions from presuppositions. Simply put, in the version deployed by Dyer, it is argued that the self, the fact that words have meaning, and logic itself (among other things) stand in need of justification if philosophical argument is to proceed. Standard philosophical argumentation concerning God typically takes these things for granted and so is never justified as a whole. The TAG philosopher argues that only God as the one and final presupposition can justify the necessary elements to make philosophical argument possible, and therefore God should be the rationally preferred presupposition.

The peculiar form of TAG often confuses and frustrates its opponents, sometimes for good reason. Familiar with starting arguments by agreeing on presuppositions, the TAG opponent is puzzled that the TAG defender won't quickly agree on presuppositions to get the discussion going, but instead wants to argue about the presuppositions themselves. Yet the whole point of presuppositions in modern philosophical discourse is that they cannot be defended or refuted but only assumed.  So argument over which presuppositions are better than others is impossible in principle. There is only personal preference based on whatever arbitrary criteria one might choose. Matt Dillahunty makes this point in his debate with Jay Dyer.

Furthermore, among the many things the TAG philosopher claims need justification are the validity of logic itself and whether words truly have meaning. But if such things are doubtful, how can they be used to arrive at reliable philosophical conclusions, including TAG conclusions?  The TAG philosopher is like a man in the year 1500 pointing out that the ship I plan to use to sail from England to America is too small and leaky to make the trip, but that he has a much bigger and more seaworthy vessel I may use. He tells me the ship is over in America, so I need only sail over there in my ship to get it, when I can then confidently sail the Atlantic. Of course, if logic is reliable enough to get us to TAG conclusions, whether they be "meta" or otherwise, it is reliable per se. If logic is too leaky and unreliable to be useful in ordinary arguments concerning God, it doesn't magically become sound just because it is used to argue to TAG conclusions.

The interesting thing about TAG, and the reason I started this post discussing Descartes, is to make a point with respect to the modern philosophical project as a whole. Recall that Descartes resolved to embark on his method of methodical doubt because he had concluded that classical philosophical dialog was a fruitless waste of time. He would set philosophy on a sound footing from which it could derive certain results. Instead the history of modern philosophy has been never ending debate concerning just what those sure foundations are. The conclusion often drawn from the never ending debate is that there are in fact no sure foundations for philosophy, only presuppositions. And as a meditation on presuppositions, TAG is a sort of logical endpoint of modern philosophy. It must necessarily operate in the gray zone implied by modern philosophy, that realm of thought that occurs before the proper method and presuppositions have been determined. Therefore its reasoning and conclusions are necessarily suspect according to the foundational principles of the modern philosophical project. TAG claims that its presupposition of God is "better" than other presuppositions, but the only way to establish this is through using the logic and reasoning that TAG claims is unjustified as part of its premises.

There is only one way forward at this point: Question the foundations of the modern philosophical project itself, i.e. that the classical dialog of opinion is a fruitless waste of time. Since modern philosophy starts with doubting things, why not doubt that?

On Darwinian Positivism

 Over at the ZMan blog,  the ZMan has a post concerning natural reason, specifically the ability of reason to answer the big questions of life: How should a man live his life? How should we organize our societies and to what end? The ZMan does not think these questions can be answered:

The truth of it is, a truth Gregory Clark surely knows, is that nature is silent on those big questions about how we ought to live and organize our societies. Nature cares about one thing and that is fitness. Specifically, every living thing is driven by its gene’s desire to make it to the next round of the game. If your genes make even a partial copy of themselves in the form of your children, that is a win. How you make that happen is of no interest to your genes or Mother Nature.

This position, which might be called Darwinian Positivism, has always struck me as manifestly absurd. Isn't it obvious that human behavior is deeper and more complex than anything that can be captured in a simple causal analysis like the "gene's desire to make it to the next round of the game?"  Voluntary celibacy may be unusual but it is hardly unknown and in fact has historically been admired as a higher form of life. The ZMan himself, I understand, has no children. 

In fact, the ubiquity of abortion and contraception in modern society would seem to clearly falsify any notion that human nature is "driven" by the gene's desire to reproduce.  In fact, we indulge in those things to the point that we no longer reproduce at replacement rate.  That is only possible if there is some other source of human behavior powerful enough to overcome any desire to reproduce.

Comment on the ZMan

 I've been following a blog from the "dissident right" written by someone using the pseudonym "ZMan."  I just made a comment on this post of his. The ZMan likes to write a lot about "fitness" and has a philosophical view that might be characterized as a kind of Darwinian positivism. I push back on some of that with the following comment. The first quote is from the ZMan's post.

“One does not logically follow the other, but the hallmark of Western thought since the late Middle Ages is the error of assuming that observations about nature or nature’s god lead to rules about human behavior.”

It goes back much farther than that, at least to Aristotle and Plato. Is it really an error to develop rules for human behavior from nature? On what else would they be based? Perhaps the most basic observation about nature that leads to rules is that people who don’t reproduce themselves will disappear from the Earth. Another is that the education of the young will play a large role in determining the shape of the future. Plato observed both these things and spent a lot of space in his Republic developing rules concerning both reproduction and education.

Aristotle further observed that the nature of man is such that he only flourishes if he develops virtue, including but not limited to the virtues of courage, self-control, justice and wisdom. A civilization that doesn’t take into account natural facts concerning reproduction, education and virtue isn’t going to last very long. A nation of sterile cowards will soon find itself It on the wrong side of the fitness to which the ZMan often refers.

Now one may disagree with the rules Plato came up with concerning reproduction or Aristotle came up with for the development of virtue. But that doesn’t mean those facts of nature or their implications go away. Yet I don’t hear much on the dissident right about the most elementary rule of fitness, which is reproduction.

Whites aren’t reproducing themselves at anything close to replacement rate. Western Europeans are somewhere around 1.5 babies per woman, and a similar rate applies to whites in the U.S. That’s a demographic catastrophe. Meanwhile, black Africans have an exploding birth rate. It’s all well and good to limit or end immigration. But unless these numbers change, Africans can eventually walk into an empty continent. (And at that point, the last people here will be black or hispanic, as non-hispanic whites have a birth rate lower than either of them.)

It’s often remarked that we can’t vote our way out of the situation we are in. We may not be able to reproduce our way out of it either. But not reproducing and educating the next generation is a guaranteed loser. You want a concrete way to help the future of the historic white people? Get married and have kids. A lot of them. Nothing else matters without it.

Kant, Doubt and Solipsism

 In an earlier post I discussed my approach to solipsism.  In brief, my approach is not to attempt to prove that solipsism is false, but to show that it is not the skeptical philosophy it claims to be. For to doubt the reality of the external world is at the same time to affirm that my own mind is responsible for everything that common sense attributes to the external world.  Solipsism can only be true if my own mind is responsible for the discoveries of Newton, Maxwell and Einstein, the plays of Sophocles and Shakespeare, the novels of Dostoyevsky, and the art of Rembrandt and Michelangelo. 

Now if instead of claiming that solipsism is doubt of the external world, the solipsist claimed that his own mind is in fact responsible for all the achievements of the individuals listed above, it would be immediately recognized that the position is not one of skepticism but of colossal intellectual arrogance. Yet the standard presentation of solipsism and my reformulation of it are logically equivalent.

I think a similar analysis holds with the philosophy of Kant. Kant's "Copernican revolution in philosophy", we will recall, holds that the forms the ancient philosophers found in nature are really constructions the human cognitive apparatus places on raw experience. So we can't know the true nature of things in themselves, but only those things as they appear filtered through human cognition. 

Like solipsism, however, the Kantian Copernican revolution can be reformulated as a claim that the forms we find in experience are generated in the human mind. The beauty of the Grand Canyon, or the singing of a lark, the majesty of the lion - from the Kantian perspective we must affirm that these are creations of the human mind, not things that come from a reality greater than us. So just as the solipsist must believe he is a mathematician at least as great as Newton, the Kantian must believe he is a creator greater than whatever is responsible for nature; God perhaps. So Kantianism isn't really the skeptical philosophy it claims to be. It is rather a colossal affirmation of the self against anything greater than the self.

The Starting Point of Philosophy

There is an absolute starting point for geometry: It is the axioms of Euclid. There is an absolute starting point for Newtonian physics: It is Newton's Three Laws of Motion. There is an absolute starting point to legal theory: It is whatever constitution is in place.

There is no absolute starting point to philosophy. There are only subjective starting points to philosophy.

The reason is that philosophy, defined as the love of wisdom, is concerned with illuminating man's own life by reason. I use the phrase own life because in the act of philosophizing, I am not attempting to illuminate your life by reason, at least not primarily, but I am attempting to illuminate my own life by reason. The starting point of philosophy, then, is each man's own life. 

Geometry and physics can have absolute starting points because their object is abstract, timeless knowledge that bears no necessary relationship to any individual's life. A man may get on well enough in life without ever knowing that the sum of the angles of a triangle is 180 degrees, or that acceleration is proportional to force.

But philosophy just is that mode of thought that concerns man in his own concrete existence. That concrete existence is the starting point of philosophy. Philosophy degenerates when it loses touch with concrete existence and turns into an indifferent playing about with concepts, an ever present temptation in philosophy.

Consider Socrates in the Crito. Socrates is in prison awaiting his execution, and Crito visits him with news that his friends are willing to bribe officials to enable his escape. Crito provides an argument as to the rightness of escaping: By remaining, Socrates is playing into the hands of his enemies, and besides he has a duty to remain alive to nurture and educate his children. It is obvious, however, that Crito is offering rationalizations that are covering, and not very well, Crito's own desire not to lose his friend. Socrates responds to Crito with the following:

For I am and always have been one of those natures who must be guided by reason, whatever the reason may be which upon reflection appears to me to be the best; and now that this fortune has come upon me, I cannot put away the reasons which I have before given: the principles which I have hitherto honored and revered I still honor, and unless we can find other and better principles on the instant, I am certain not to agree with you; no, not even if the power of the multitude could inflict many more imprisonments, confiscations, deaths, frightening us like children with hobgoblin terrors.

The import of Socrates's response is that as a philosopher, his life is guided by reason, and that means he must submit to his reason in the here and now, when fortune has turned against him, just as he did in happier times discussing philosophy pleasantly in the agora. Were Socrates to rationalize an escape, he would falsity his own nature as a philosopher, a fate Socrates fears more than imprisonment or death.

The fact that there are only subjective starting points to philosophy, and not an absolute starting point, does not mean that philosophy is purely relative or can't gain a knowledge of the truth. The starting point of philosophy is not absolute, but the end point may very well be. We may start our travels in different cities, but it doesn't follow that our destinations must be different.

What is the absolute end point of philosophy? It is the Absolute Being Who is the Source of each of our individual, contingent beings. It is in the light of that Absolute Being that our own lives will finally become intelligible.

Cosmic Skeptic and the Moral Argument for the Existence of God

 The Cosmic Skeptic (Alex) has an interesting video ranking the arguments for the existence of God here.  The video is a discussion between the Cosmic Skeptic and Joe Schmid, who we learn is an agnostic.

In this post I'd like to address the discussion of the Moral Argument for the existence of God. That occurs at 1:28:40 of the video. As presented, the Moral Argument is formulated this way:

P1: If God does not exist, then objective moral values do not exist.

P2: Objective moral values do exist.

C: Therefore, God exists.

The conversation notes that P2 may be denied, but they leave this aside as they are more interested in whether the existence of God does in fact follow if moral values exist. Joe Schmid asks an interesting question: What does God add to the question? When God commands something, he either has a reason for the command or he doesn't. If God doesn't have a reason, then he is arbitrary. If God has a reason, then it is that reason that is significant, not the fact that God has commanded it (I am paraphrasing here.)

As they note, this is a version of the Euthyphro dilemma from Plato. Schmid thinks his version is stronger than Plato's, because Plato is concerned with what makes things right or wrong, whereas Schmid's argument just refers to whether God has a reason or not.

They then get into a discussion of God's relationship to goodness, and raise the idea that goodness just is being more like God. They raise some problems with it,  for instance that if God is immaterial, then I am somehow better if I become immaterial, which doesn't seem to make sense. Schmid argues that God is simply acting as intermediary, because it is the loving, the kindness (as concepts) that are doing the heavy lifting, not God. It is the intellectual and moral virtues themselves, not God.

Alex then brings up a functional account of goodness.  A chair, for example, is a good chair to the extent that it fulfills its designers function for which it was made. It seems odd, however, to speak of it as a bad table even if it can be used as a table. 

They discuss the idea that moral values are doing what God designed us for, but they find that this is arbitrary as well, for God could have simply proclaimed the function of women is to be raped. Antecedent to God's design, there are no moral facts God is looking on in terms of which to structure his designs or define their functions. 

Alex brings up what he considers an equivocation between the functional use of "good" and "bad", i.e. in describing a chair as good or bad depending on how well it serves as a chair, and "good" and "bad" as used in moral language with respect to people, which is not merely functional.  The language of virtue used with respect to people is not used with respect to chairs.

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The conversation could have used an exploration of a Thomistic understanding of good and evil. What happens in God's creative act? He gives a nature and existence to a being. Embedded in the nature of the being are formal and final causes that give substance to that nature. They implicitly define good and evil with respect to that being. Were God to then command something in contradiction to the natures he has created, he would simply be contradicting himself.

Suppose a piano maker builds a beautiful piano, paying attention to the smallest details to make the instrument easy to play and so it will produce a beautiful sound.  He tunes it painstakingly so every string is in tune with every other.  Then, when he is finished with it, he never plays it, but instead sleeps on top of it because he has declared the function of the piano to be a bed.

We would find the piano maker ridiculous. His construction of the piano was built under the obvious plan that the function of the piano would be as a musical instrument. To then use it as a bed is simply to contradict everything the piano maker implied in his construction of the instrument. We might argue that the piano maker's choice to use the piano as a bed is an act of "freedom", but whether we wish to call it free or not, it nonetheless contradicts everything the piano maker did in construction the piano. "Freedom" to frustrate your own designs is a degenerate form of freedom.

When God creates, he creates natures with embedded formal and final causes. A dog has a certain nature and a certain mode of being; his life is centered around scent and is naturally sociable. If God then commands that dogs should always be kept in isolation and live in water,  this would contradict what God did in  the creative act that established the nature of dogs in the first place. Contradicting himself is not a "power" that an omnipotent creator need have, because it is actually an expression of impotence, not power.

So with respect to Schmid, God does not reference some already existing values in his creative act. He establishes good and evil with respect to particular natures in the very definition of those natures; just as playing a piano well is defined with respect to the inherent potentialities of the piano as a musical instrument.  To be good is simply to be in the best way with respect to individual nature. To be evil is to not be in some way that is appropriate for a given nature.  God won't command that women should be raped because that would contradict the good for women that was defined by God in creating women in the first place. 

Man is the particular subject of moral judgment because, unlike dogs and tables, he has an intellect and will that can perceive good and evil and act accordingly.  So to be a good man involves having a good intellect and a good will, which is not involved in being a good dog.

And what about the Moral Argument for the Existence of God itself? I am not a fan of it, because it seems to assume a certain arbitrariness with respect to morality, as though morality is layered on to already existing being, rather than being embedded within natures themselves when they are created.  The appropriate way to argue from morality to God is not to claim that the atheist can't know moral values without knowing God, but to argue what the knowledge of morality implies about the nature of being and its foundation, i.e. something like Aquinas's Argument from Perfection.

Common Sense Realism and Modern Philosophy

Common Sense Realism 

I call "common sense realism" any philosophy that takes ordinary experience as generally reliable. I consider myself a common sense realist, and I will use CSR as a shorthand for "common sense realism."

The designation "common sense realism" has some use in the history of philosophy, particularly with respect to Scottish philosophers including Thomas Reid, but I'm using the term for my own purposes independent of that history.

We all follow CSR in everyday life. Everyone goes through life taking for granted, most of the time, that what is presented to his senses is the way things are. They see the sun and don't doubt it is the sun they are seeing, they hit a baseball and don't doubt that the bat caused the baseball to fly, and they greet their wife not doubting that she is the same woman they greeted yesterday. This holds true for modern philosophers of the skeptical, analytical or Kantian variety as much as it did for Aristotle. 

The greatest advantage of CSR, an advantage I find nearly decisive, is that when reflecting philosophically on experience, CSR doesn't demand that the philosopher toss everyday certainties out the window. The philosophy he develops is the same philosophy by which he lives everyday.  He avoids the fracturing between life and thought that inspired the title of this blog. 

That fracturing was puzzling when I noticed it in college philosophy classes. We discussed what might be believed or doubted with respect to our experience and our morality, but those philosophical beliefs and doubts seemed to have little to do with how any of us, students or professors, actually conducted ourselves outside of class. This impression of philosophy proved enduring, and I developed the "private book" vs "public book" distinction to describe it. 

Organized crime keeps two sets of accounting books, the public book it presents to the courts and investigators, and the private book it keeps hidden that is the true account of the organization's finances.  Similarly, philosophers seemed to have a "public book" that reflected their "official" philosophy they presented in class and in journals, and a "private book" of beliefs by which they actually ran their lives. It was only many years later and after reading certain philosophers - especially Kierkegaard - that I began to understand that this fracturing was not accidental.

Prior to the modern era - which I will define with usual starting point of Descartes - the mainstream of the philosophical tradition followed CSR.  But there were exceptions. The Ancient Greek philosopher Heraclitus, noticing the constantly changing nature of the material world, concluded that flux was metaphysically basic and that CSR was mistaken. CSR says the river behind my house today is the same river it was yesterday, but Heraclitus would insist this is an illusion: You can't step into the same river twice. On the other hand, the philosopher Parmenides, seeing that nothing comes from nothing, and that being is and non-being is not, concluded that change is an illusion and that reality is static, since any change from non-being to being would be an instance of something coming from nothing. These philosophers did something that would become recurrent throughout history: They saw part of the truth but became so captured by it that they ignored the rest of the truth. 

What distinguishes Heraclitus and Parmenides from CSR philosophers is that the former ended up insisting that ordinary experience is at bottom an illusion. We might think things endure through time, that the tree in my yard yesterday is the same tree that is there today, but Heraclitus would tell us that I'm naive to think so. I might think that tree grew from a sapling over the years, but Parmenides would deny that it had ever really changed at all. 

The most famous and enduring CSR philosopher is Aristotle. Against Heraclitus, Aristotle noted that if everything was in flux, then there would be no possibility of knowing the truth. And since we manifestly do know some truth, that position cannot be correct. Against Parmenides, Aristotle pointed out that change is a manifest aspect of reality, which his position denies. His developed response to these philosophers resulted in the hylomorphic theory of being, the distinction between matter and form.

But what makes Aristotle a CSR philosopher is not his hylomorphism, however.  Hylomorphism is just one way to develop a CSR philosophy.  Aristotle was a CSR philosopher because he defended ordinary experience against radical skepticism. He gives an expression of CSR in his Metaphysics:

There are, both among those who have these convictions and among those who merely profess these views, some who raise a difficulty by asking, who is to be the judge of the healthy man, and in general who is likely to judge rightly on each class of questions. But such inquiries are like puzzling over the question whether we are now asleep or awake. And all such questions have the same meaning. These people demand that a reason shall be given for everything; for they seek a starting-point, and they seek to get this by demonstration, while it is obvious from their actions that they have no conviction. But their mistake is what we have stated it to be; they seek a reason for things for which no reason can be given; for the starting-point of demonstration is not demonstration. (Metaphysics, Book IV, Ch. 6)

Aristotle criticizes his opponents by saying that "it is obvious from their actions that they have no conviction."  How do we interpret this? Notice that he compares his opponents to those who wonder whether they are asleep or awake. Such people typically behave as though they know very well that they are awake. If they thought they truly might be in a dream then they would struggle to wake up. But they don't struggle. In fact, they behave as though they had no doubt they are awake. Their doubt has no conviction and need not be taken seriously.

For the CSR philosopher, the lack of conviction in such objections is enough to dismiss them. Philosophy for him is not a game, a hobby, or merely something to teach in the classroom, a way to make money. It is the penetration of life with reason, this life, the one I am actually living. He is always on guard to prevent the fracturing of his life with his thought.  No one can get through life with the conviction that everything is in flux, or that change is impossible. The only way to hold such positions is to fracture life and thought, to live by one philosophy and think by another. 

The Modern Philosophical Era

I noted earlier that prior to the modern era the mainstream of philosophers were CSR.  What distinguishes the modern era is that philosophers are typically not CSR. In fact, very often a modern philosopher develops his philosophy specifically as a rejection of CSR. If for the CSR philosopher the greatest sin is to lack conviction (i.e. to allow a fracture between life and thought), for the modern philosopher the greatest sin is to be "naive", and CSR philosophers are at the top of the list of naive philosophers as far as modern philosophers are concerned. 

Over the years the modern philosophical view has percolated through the culture, down to the level of the ordinary man. At that level it manifests itself in an impression that the business of the philosopher is to doubt everything, or to hold eccentric views that challenge the common sense of the ordinary man. The philosopher is the man who has "seen through" the naive dogmas and prejudices of the ordinary man to the truth beyond it.

Descartes established the pattern for modern philosophers and can be taken as the starting point for philosophy in its distinctively modern sense.  Although subsequent philosophers rejected many of his specific conclusions, the general form Descartes gave to modern philosophy has persisted. 

As a young man surveying the education he had received, the impression Descartes had was that the centuries of classical philosophy had produced nothing of any certainty. The philosophers were still arguing the same points they always had:

Concerning philosophy I shall say only that, seeing that it has been cultivated for many centuries by the most excellent minds that have ever lived and that, nevertheless, there still is nothing in it about which there is not some dispute, and consequently nothing that is not doubtful... I deemed everything that was merely probable to be well-nigh false. (Discourse on Method, Part One)

 He conceived a way out of this (alleged) futility: He would embark on a campaign of radical doubt, not accepting anything unless it could be demonstrated with absolute certainty:

,,, I thought it necessary that I do exactly the opposite, and that I reject as absolutely false everything in which I could imagine the least doubt, in order to see whether, after this process, something in my beliefs remained that was entirely indubitable. Thus, because our senses sometimes deceive us, I wanted to suppose that nothing was exactly as they led us to imagine... (Discourse on Method, Part 4)

We may note that the campaign of doubt on which Descartes began may not be as straightforward as he imagined.  Remember that Descartes was led to his radical doubt because he concluded from the history of classical philosophy that it was futile. Well, if he's going to doubt everything that might be doubted, should not his conclusions with respect to classical philosophy be doubted? Maybe classical philosophy wasn't as futile as he supposed. Perhaps his own understanding of it was worthy of doubt.  We may recall the following passage from Plato's Phaedo, where Socrates addresses the frustration his friends felt at their inability to arrive at a conclusive argument with respect to the nature of the soul:

Well, then, Phaedo, he [Socrates] said, supposing that there is an argument which is true and valid and capable of being discovered, if anyone nevertheless, through his experience of these arguments which seen to the same people to be sometimes true and sometimes false, attached no responsibility to himself and his lack of technical ability, but was finally content, in exasperation, to shift the blame from himself to the arguments, and spent the rest of his life loathing and decrying them, and so missed the chance of knowing the truth about reality - would it not be a deplorable thing? 

But Descartes chose to doubt the whole of the philosophical tradition rather than himself. We might also note that Descartes's assertion that "our senses sometimes deceive us" is not an expression of doubt but rather of knowledge, for an instance of deception that is known as such really isn't an instance of deception, and anyways witnesses to the more general case of the reliability of the senses. For instance, a straw seen in a glass of water appears bent to us due to the refraction of light at the boundary between air and the water. We take the straw out of of the water and we see that it is straight. We might classify the former case as an instance of our eyes "deceiving" us, but that conclusion only stands on a conviction that in the latter case our eyes are not deceiving us. 

That all notwithstanding, Descartes's method of doubt eventually led him to the one proposition that he thought could withstand doubt: An assertion of his own existence. He must exist in order to be deceived, and so I think therefore I am,  the famous Cogito Ergo Sum.

The Cogito is sometimes interpreted as the first proposition that Descartes "could not doubt." That is not quite correct. It is the first proposition that Descartes found could withstand doubt. For Descartes definitely doubted it. He just overcame that doubt with an argument: If he is deceived, he must exist to be deceived, therefore he exists. 

Descartes congratulated himself on making a novel discovery with the Cogito, but in fact all he had done was rediscover a metaphysical principle well known to CSR philosophers: Being is prior to act. The assertion of an act implies the existence of the being for whom it is an act. Flute playing implies a flute player, thinking implies a thinker, dancing implies a dancer, and deception implies one who is deceived.  

Where the CSR philosopher differs from Descartes is in recognizing that this metaphysical principle is something immediately known through experience, not something that is known only after surviving trial by doubt. As soon as someone sees and hears a flute player, he knows that the flute playing depends on the flute player and would not exist without him. He knows it so immediately that his mind ordinarily does not stop to reflect on the fact but moves on to other things. All the CSR philosopher does is slow the mind down to conscious reflection on the elements known through experience, elements that the mind normally glosses over in favor of more pressing things requiring attention.  The fact that the mind normally glosses over basic metaphysical principles immediately known to it in no way makes them doubtful; Thinking it does is a mistake at the heart of modern philosophy.

Philosophy and Method

While subsequent philosophers rejected many of Descartes's specific conclusions, they embraced his basic approach. Specifically, that philosophy must begin with method. Thinkers at the time, in the 17th and 18th centuries, were understandably impressed with the successes of the new scientific approach that was unlocking the secrets of nature.  The new science exploded many things thought to be true based on an Aristotelian approach and brought the Aristotelian tradition as a whole into question. Aristotle, for instance, taught that objects like stones fall toward the center of the Earth because that is their natural place to be as heavy objects, as opposed to light objects like fire that travel away from the center towards the periphery. The developing science of Newton, however, not only explained the motion of objects much more fruitfully and accurately than an Aristotelian approach, but did so in a way that seemed to dispense with Aristotelian notions, like final and formal causes, entirely.

Philosophers noticed the emphasis on method in the new science and, hoping to mimic science's success, made again the mistake that recurs in the history of philosophy: The mistake of absolutizing an aspect of the truth into the whole of the truth. In this case, they took the newly discovered truth concerning the methods of modern science, which does in fact provide a new and reliable way of interpreting empirical nature,  to imply that all thought must start with method to be reliable.

This is where they agreed with Descartes. Where they disagreed is just what the appropriate method for philosophy should be. Descartes thought it was his method of "universal doubt."  Locke proposed instead his "plain, historical method", which was highly influential and colored much of the discussion of method in philosophy after him, including the philosophy of David Hume. Ultimately there came the method of "critical philosophy" of Immanuel Kant, a monumental attempt to get at what might be described as a "method of methods" in thought.

It's understandable why there was such disagreement over what constituted the proper method of philosophy.  For if we can only trust our thought when it is disciplined by method, then the thought that determines method is unreliable, since it is necessarily prior to method and therefore undisciplined. In one of the many ironies generated by modern philosophy, the method by which modern philosophy would transcend the alleged uncertainty of CSR could itself only be determined by thought in a gray zone that was, if anything, even more uncertain than CSR. Descartes, naturally, was the first to operate in the gray zone when he justified his adoption of the method of universal doubt by a biographical account of his subjective impression of classical philosophy. 

The lesson subsequent philosophers took from Descartes was not to mimic his universal doubt, but  that they were as free as Descartes to operate in the gray zone and establish philosophy on a method of their own invention. The most notable of these was  John Locke and his empiricist "plain, historical method."  Locke's selection of method became very influential, perhaps because it was explicitly developed to support the new science that had so impressed the 17th and 18th centuries.

Science and Philosophy

In their haste to learn lessons from the newly developing science, philosophers overlooked a few important features of science. The most important of these is that scientists themselves, in conducting science, operated in the common sense world of CSR.  When Galileo looked through his telescope at the moons of Jupiter, he took for granted that his telescope was what his common sense thought it was, that the dots of light he observed in the sky represented celestial objects that were the same objects he had observed the night before, and that various other common sense notions of cause and effect were reliable. He did not think that his vision of Jupiter was actually a blob of color organized by his mind into something resembling a planet, and having only a dubious relationship to external reality,

To doubt CSR is to doubt the basis on which science is actually conducted. The skeptical arguments of David Hume were most devastating in this regard. Hume argued that from a strictly empirical perspective, we see through our eyes colors and shapes, but we do not see causes that link one thing to another, nor do we see the substance that is claimed to be the basis of enduring identity.  I see a tree in my yard today and remember seeing a tree there yesterday, but what I do not see is the principle that this is the same tree as yesterday. I see the brick thrown at the window and the window shatter, but I do not see the brick caused the window to shatter.  The enduring identity of the tree on the one hand, and the causal link between the thrown brick and the shattered glass on the other were, Hume claimed, but "habits of the mind" developed through repetition rather than empirical principles read off sense data.

The response of CSR to Hume is that while empirical data comes through the senses, it doesn't follow that everything in that data is grasped by the senses, any more than your mailman knows the contents of all (or any) of your packages. The senses themselves grasp being in its material particularity; the intellect grasps the universal nature of being encountered through the senses. It is the intellect that knows that the same tree I see today is the same as yesterday, not the senses. 

Hume's skeptical empiricism pulls the rug out from empirical science, as was recognized by perhaps the greatest of Enlightenment philosophers, Immanuel Kant. Kant wanted to preserve the certainty of science, as well as establish philosophy on a permanently firm foundation. Rather than propose yet another philosophical method developed more or less arbitrarily, the variety of which proved that philosophers had yet to penetrate to the depths of the problem, Kant took the analysis to another level with what he called the a priori in his "critical philosophy." The a priori seeks to get behind experience to explore the conditions that make experience itself possible in the first place. The endurance of identity over time, for instance, which we might give the name substance,  isn't a concept our minds draw from experience already given to us, whether legitimately (as CSR holds) or illegitimately (as Hume held.)  Kant argues that it is a condition we must presuppose for there to be any experience at all. In that sense it is far more certain than Hume imagined. 

Thought and Being

What is fascinating about Kant is that in developing his critical philosophy, he reconstructs much of the Aristotelian infrastructure, only instead of basing it in being, he bases it in presuppositions of thought. In other words, instead of being out there in the world, it is only inside our heads as something we must assume. This is the result of denying the reality of the human intellect's relationship to being.

We might ask why we should go through the arduous journey of critical philosophy (Kant's Critique of Pure Reason is no easy read) only to arrive back at Aristotle, and an Aristotle that is imprisoned in our own minds. Kant's answer was that the limits of reason had now been firmly established and philosophers were no longer in danger of making the metaphysical mistakes of the classical philosophers. Philosophers were no longer "naive."

Looking at philosophical history post-Kant however, that basis wasn't established nearly as solidly as Kant thought. From an even loftier "meta" level, Kant's efforts look like just another attempt to find an absolute starting point to philosophy, not essentially different from Descartes's. 

This brings full circle the philosophical project begun by Descartes. The basic mistake Descartes made, putting thought prior to being, became the fundamental move of modern philosophy. It remains to ask why such a mistake is so tempting. Since being is in truth prior to thought, the answer should be an answer in terms of being, and being's implications for thought.

Man's being is that of a rational animal. He is animal insofar as he is a material being existing in time and space. He is rational insofar as he has an intellect capable of knowing universal being. Your dog encounters this tree and that tree in its life, but does not know each tree as expressing the universal nature of tree that your intellect grasps.

The incarnate aspect of man's rationality has significant consequences. Through his senses his intellect grasps being, but it is only this or that being of the contingent objects encountered in experience. The mind grasps the being of this tree as one tree among many, true, and as the same tree as yesterday.  But it also sees that the being of the tree does not account for itself. There are mysteries at the heart of contingent being: Why do this tree and that tree share the mutual nature of tree? Just what is the universal nature of tree?  The tree yesterday and today persists in its being, but there is nothing in the nature of tree as such that seems to make it so.

The classical philosopher does not see these questions as reasons to doubt the intuition of being itself, i.e. common sense is not overthrown simply because it is not perfectly transparent. Instead he uses these intuitions of being to demonstrate the reality of Absolute Being (i.e. God) that underwrites the contingent beings of our experience.  The proofs in this regard are relatively straightforward and pretty much unassailable given CSR.  That is why atheist philosophies since the early modern era find that in attacking the existence of God, they must first attack the existence of common sense.

Be that as it may, the temptation to which modern philosophies succumb when faced with the opacity in contingent being is to fall back on the clarity the mind has in its own ideas. It may be mysterious why the tree yesterday continues to be the same tree today, but it is no longer mysterious if I assume that my mind generated the persistent identity; there is nothing more in the idea than what my mind put there. Problem solved.

Only it isn't solved, only denied, and at the cost of destroying common sense and fracturing life and thought. 

Thus, even those who appreciate the metaphysical depths of Thomism in other matters have expressed surprise that he does not deal at all with what many now think the main metaphysical question; whether we can prove that the primary act of recognition of any reality is real. The answer is that St. Thomas recognized instantly, what so many modern skeptics have begun to suspect rather laboriously; that a man must either answer that question in the affirmative, or else never answer any question, never ask any question, never even exist intellectually, to answer or to ask. - G.K. Chesterton, Saint Thomas Aquinas