Classical Apologetics, Metaphysics, Philosophical Theology

The Presuppositionalism of René Descartes

by Dave Seng

Note: I discuss a few of these thoughts regarding the presuppositional method of apologetics here. In this post I will look at a 17th century version of presuppositionalism drawn from Rene Descartes, who is often considered the father of modern philosophy.

The more I read the great authors of the western intellectual tradition, the more I realize there really is nothing new. This occurred to me once again when I was reading through the works of René Descartes and discovered that he maintained a presuppositional bent in his argumentation for God’s existence. This experience took me back to the time when I first learned the basics of philosophical theology and apologetic method. Like most who begin exploring the field of Christian apologetics, I was introduced to the presuppositional school of apologetics. Mostly, I read Greg Bahnsen, Cornelius Van Til, Gordon Clark, and John Frame. I read other authors related to the presuppositional school but I never found the method to be conceptually coherent or rationally compelling. Interestingly enough, when I went back to re-read Descartes for my doctoral work, I discovered that presuppositional apologetic thinking is not new, certainly not just a twentieth or twenty-first century phenomenon, and the same problems with the method still apply.1 (In many ways the presuppositional school of apologetics closely corresponds to Kantian transcendental idealism and German idealism in general such as Kant, Hegel, Schelling, etc., but that is a topic for another post.) By “presuppositional method” I am referring to any apologetic approach that presupposes the truth of Christianity or the Christian God and then reasons from that point.

I especially enjoy reading the earlier thinkers who contribute to philosophy and theology because they often shed light on today’s intellectual issues and thinking in ways that might be overlooked or missed. I’ve read Descartes many times in my academic career and the presuppositional character of his work went unnoticed. Only recently did it stand out to me. That’s the great thing about reading a truly classic author. One can always learn something new.

To begin, Descartes was a rationalist. In contrast to other philosophers, who take the reality of Being as a fact and use that fact (derived from sense experience) as a point of philosophical departure, rationalists such as Descartes think that the truth about reality can be acquired by reason alone. This is an important point which explains why he thinks God must be presupposed when it comes to explaining the nature of reality.

Descartes presents a presuppositional argument for the existence of God based on the idea of God as a Perfect Being. To be fair, Descartes presents several different arguments for God’s existence in his writings. Here, I am mostly concerned with his presuppositional approach found in his Discourse on the Method of Rightly Conducting Reason, and Meditations on First Philosophy. All his arguments, however, are rational in nature (appealing to reason alone) and based on the idea of God, and establishing the existence of God based on geometrical argumentation. Descartes’s Perfect Being argument is similar to the ontological argument, a kind of proof for God’s existence: God must exist inasmuch as the attribute of existence or, in some forms, necessary existence, is part of his nature. Descartes version of the argument simply contends that a Perfect Being must exist because existence is property of perfection. Descartes attempts to demonstrate that God can be proved the same way one can rationally solve a geometrical equation, simply by following the rules of reason. While contemplating the axioms of geometry, Descartes applies the same rational mathematical reasoning to the existence of God,

For to take an example, I saw very well that if we suppose a triangle to be given, the three angles must certainly be equal to two right angles; but for all that I saw no reason to be assured that there was any such triangle in existence, while on the contrary, on reverting to the examination of the idea which I had of a Perfect Being, I found that in this case existence was implied in it in the same manner in which the equality of its three angles to two right angles is implied in the triangle; or in the idea of a sphere, that all the points on its surface are equidistant from its centre, or even more evidently still. Consequently it is at least as certain that God who is a Being so perfect, is, or exists, as any demonstration of geometry can be. (277)

Descartes Perfect Being exists the way a triangle exists—it must exist the way a triangle has two right angles. In other words, God must be presupposed the same way one presupposes the principles and axioms of mathematical truths. Descartes is aware that such a rational attempt may not be very convincing for some. Following his method of extreme doubt, Descartes shifts his approach and asks about the reliability of our thoughts during a dream. Can we doubt our thoughts and imagination the same way that we doubt our senses? Descartes provides this answer,

And though the wisest minds may study the matter as much as they will, I do not believe that they will be able to give any sufficient reason for removing this doubt, unless they presuppose the existence of God. For to begin with, that which I have just taken as a rule that is to say, that all the things that we very clearly and very distinctly conceive of are true, is certain only because God is or exists and that He is a Perfect Being, and that all that is in us issues from Him. (277, emphasis added)

Notice what Descartes is saying here—one must presuppose God exists because God is a Perfect Being which must include existence. In other words, God is (presupposition), therefore God exists (because a Perfect Being must exist). This is the heart of the presuppositional approach. And it is entirely circular in reasoning. But before we get to the analysis of Descartes approach and the presuppositional method, it is best to look at his basic points of departure.

To summarize, Descartes reasoning is as follows: one can not trust the senses because the senses can be wrong. However, as Descartes famously observes “I think therefore I am”, and he concludes that he can in fact trust his reasoning, because he has to exist in order to think (275, 276). Further, Descartes thinks that because he can think of a Perfect Being, God must exist. God must exist because existence is a property of Being and in order to be the most Perfect Being, such a Being must have the property of existence. Descartes calls this a “metaphysical certainty” (277). If one doubts such a metaphysical certainty, they should presuppose God exists because he reasons that God’s existence will solve the doubts one can experience from thoughts, dreams, imagination, or the senses. In other words, one must presuppose that God exists in order to make sense out of the reality of the world. Descartes makes this even more clear in his Meditation on First Philosophy,

And we must not object that it is in truth necessary for me to assert that God exists after having presupposed that He possesses every sort of perfection, since existence is one of these (320).

For Descartes, God exists because it is presupposed that God has perfection. It is worth pointing out that not every theist that holds to the ontological argument, or Perfect Being theology, is a presuppositionalist or must be a presuppositionalist in order to defend it. Here, I am merely pointing out that Descartes does make his presupposition of God’s existence a central point in his argument for God’s existence. Descartes needs to make this philosophical assertion because he can not start with the trust worthiness of Being or reality itself (for him, those things must be doubted). His argument must be purely rational because that is the only starting point that will provide certainty for him. Descartes philosophical theology is unique in the sense that he does not take Being as his starting point but focuses on rational geometrical proofs and the need to presuppose the existence of God as the foundation of his method. For Descartes, God is a Perfect Being which must be presupposed.

Now a few concluding thoughts about Descartes and presuppositionalism can be said. First, there is nothing inherently wrong with a pure rational argument for God’s existence. Plato would have have agreed with some of Descartes ideas. Many mathematicians have come to theistic conclusions based on the symmetry and principles of math itself. Many, I think, are valid. The problem is that starting with the existence of God and then arguing from that point is bad logic. The thing that always prevented me from taking the presuppositional school of apologetics seriously is the the circularity of the method. Circular reasoning is a logical fallacy which is formally called the petitio principii (begging of the question). This is an error that occurs when when the conclusion of an argument is already present, usually disguised or vague, in the premises. It is seen as circular because the conclusion is present in the premises, and no real progress is made. A more modern example of circular reasoning is this, “You can’t expect seventeen-year-olds to vote intelligently, because they are too young to have good judgment about the issues.” The conclusion of the argument is one of its premises. When the conclusion is one of the premises, the argument is circular and begs the question. Descartes reasoning that God must be presupposed to show that God exists is circular. Finally, it makes little practical sense to tell the non-theist that they must presuppose the existence of God when the existence of God is the central question.

There is another issue with rationalism more generally. Much of modern philosophy, beginning with Descartes begins with epistemology (how we know what we know). When one begins with how we know, and not the metaphysical givenness of reality, a pure rational epistemology can quickly go circular. Descartes gets things only half right here. Existence is a property of being. But there are different orders of being and different kinds of existence. My thought of a flying unicorn with laser beams shooting out its eyes has a very different kind of being than the tree in front of my house. Imagination presents a different mode of being than physical reality. Angels have a very different kind of being than I do. There are different orders to being and different kinds of existence. Descartes is making a rational or conceptual statement and applying it to concrete reality, when in fact, the question really is whether or not such a Perfect Being exists absolutely, not rationally or conceptually. The theist and non-theist can both have the same conception of a Perfect Being but the issue at stake is whether or not such a being actually exists. Starting with what-is and understanding the order of being (and order of knowing) is a far more fruitful project.

It is worth noting here that Benedict Spinoza assumes much of the Cartesian methodology and presuppositions. However, Spinoza was lead through his rational conception of Perfect Being theology that God and the world are one. For Spinoza, pantheism was the logical outcome based on his Cartesian rationalism and presuppositions. Presupposing the existence of God on strict rational grounds does not prevent one from becoming a pantheist. In other words, presupposing that God exists does not necessarily lead one to Christian theism.

As I will always try to explain, when one begins with epistemology, and make that one’s starting point, instead of metaphysical realism, or the givenness of Being, things go bad in philosophy and one’s approach to apologetics.

1Benedict Spinoza in his Ethics often assumes Descartes’s presuppositional outlook, but I hope to develop that later. Interestingly, the father of presuppositionalism, Van Til, developed his school of apologetics based on ethical concerns.

Works Cited

Descartes, Rene. Bacon, Descartes, Spinoza. Great Books of the Western World. Vol. 28. Encyclopedia Britannica, Inc., 1999.

Metaphysics, Philosophy, Uncategorized

The Fantastic Four

by Dave Seng

It has been a while since I made a “top four” post. Here are the four most popular articles of 2021, in case you missed them the first time around. I will continue our study of democracy soon. Enjoy!

  1. Lutheran Scholasticism and Aquinas (still seems to be a favorite).
  2. Aristotle and Augustine on Being, Truth, and Logic, Pt. 2
  3. More Than A Feeling: Metaphysical Intuition in Aristotle and Bergson, Part One
  4. Plato’s Metaphysical Answer to the One and the Many, Part Two
Intellectual History, Metaphysics, Philosophy

Aristotle and Augustine on Being, Truth, and Logic: Part One

by Dave Seng

It is right also that philosophy should be called knowledge of the truth.–Aristotle

If truth is genuinely true, then it will be discovered regardless of one’s philosophical outlook or frame of reference. For example, Aristotle and Augustine have both discovered important metaphysical connections between the perennial questions of truth, reality or being, and the metaphysical principles that make being a possibility in the first place. Although it might be unusual to find connections between Aristotle and Augustine, due to their different methods and perspectives, it should not be surprising that they arrive at similar conclusions. Even though each thinker has a different metaphysical starting point and prior commitments (Augustine being a Platonist, and Aristotle utilizing a more empirical and inductive approach) there is still a lot of common ground between the two philosophers. As I will demonstrate, there are several reasons for this shared commonality. Each thinker has a commitment to discover truth and believes real knowledge about the world and ultimate reality is possible. Since reality, itself, is the determinant of order (not one’s theories about it, because those could be wrong), it should not be surprising that each thinker arrives at similar conclusions even if each is employing different approaches.1 The structure of reality is not different for either philosopher. Even though each thinker is working in different historical eras and regions of the world, truth still endures across time and space. In addition, it may be discovered that each philosopher’s approach, though different, is actually complementary to one another. For this essay, the specific overlapping areas between these thinkers are the themes of being, truth, and the role of logic as foundational to understanding reality. Hopefully, it will be discovered how these great ideas and intuitions of being, truth, and logic must be among the first principles of reality.

First, it is important to have a working definition of being before making an analysis of each philosopher’s position. Being is the object of study of metaphysics (the branch of philosophy which investigates the first principles and causes of all reality). Being is simply that to which existence belongs, and it is the task of the metaphysician to describe the causes, principles, and limitations which belong to different kinds of things. It is believed that understanding the modes and properties of being through the philosophical lenses of being and becoming, or being and non-being, that a greater apprehension of reality is achieved. Being is the exploration of reality, although, it may include more than physical reality because the metaphysician is also interested in how immaterial things like mathematics (including the axioms and laws of logic such as noncontradiction, identity, and excluded middle), the mind or intellect (or at least, objects of the mind), and moral truths such as justice, the good, or the concepts of right and wrong, relate to being. Metaphysicians explore the question, “Is there an ultimate foundation to these things that make them possible?” Therefore, when Aristotle, Augustine, or any other classical metaphysician discusses themes such as being and truth, or logic, they are investigating the first principles of reality and how they relate to the world around us.2

It is important to point out as Plato, Aristotle, Augustine, and Aquinas do, that there is a transcendent and universal quality to being. Briefly, these philosophers believe there is a transcendent nature to being because it is a universal concept just like truth, goodness, justice, and human nature (among others) are. These concepts are considered transcendent and universal because any number of particular things can participate in them. For example, many particular people can pursue justice and even experience instances of it. To the degree that a particular instance of justice is genuine, it resembles or takes part in the universal and transcendent definition of what it means to achieve justice which is true at all times and places. This is why an historian can say that a particular event in the past is just or unjust3. Similarly, when Aristotle says, “being is predicated of all things” (588), he is saying that being is a universally transcendent concept. Just like truth, justice, and the good, being must be transcendent and universal in order to make any meaningful statements about it.

We now have a reasonable understanding of what being is and why it is considered a universal. In part two we will examine the relationship between being and truth and explore important commonalities between the perspectives of Aristotle and Augustine.

1Reality, here, is used to indicate that which exists outside the human mind. In this sense, reality is the determinate of order because sometimes there is a real difference between appearance and reality, just as there is a difference between our theories of reality (epistemology) and reality itself (ontology). Moving on in this essay, however, the term “being” will be used to include all of reality which can be divided along the lines of subjective and objective, mental and external, actual and possible, and so forth.

2Although there were those before him who touched on the question, Aristotle posed the question of being this way, “And indeed the question which was raised of old and is raised now and always, and is always the subject of doubt, viz. What being is, is just the question, what is substance” (Vol. 7, 550). In this passage, some translations describe “substance” as “beingness” which might be more helpful. Substance, of course, for Aristotle was a combination of form, or essence, and matter (essence being the limiting factor of matter). Nonetheless, the question of being is a perennial one.

3Here, it is claimed that although the past no longer exists, it is a real object of study and perceptual thought and, therefore, has reality. That is, it has being and is related to being even though it is no longer in act or has actual existence. Humans are cognitively wired in some way to discern the past. Moral truths apply to history because of their transcendent nature.

Intellectual History, Metaphysics, Philosophical Theology, Philosophy

Aristotle’s “Being” as The Ground for Theology

by Dave Seng

The most exact of the sciences are those which deal with first principles – Aristotle, Metaphysics, I.2.

Interestingly enough, one of the earliest writers in the Western intellectual tradition to talk of theology as a specific field or area of investigation is Aristotle. In fact, Aristotle believes that theology (a systematic pursuit of the knowledge of God) should be considered among the first principles of reality. Aristotle’s explication of theology as a part of metaphysics has interesting implications for a Christian approach to philosophical theology and the underlying question of the connection between faith and reason. If Aristotle is correct in his position, Christians should adopt it, just as Augustine believes there is much to be gained from the insights of philosophers outside the Christian faith. For example, in his book, On Christian Doctrine, Augustine tells us, “If those who are called philosophers, and especially the Platonists, have said aught that is true and in harmony with our faith, we are not only not to shrink from it, but to claim it for our own use from those who have unlawful possession of it” (737). What Augustine believes is true of Platonic philosophy can also be said of the teachings of Aristotle. Christians should not fear philosophy or shy away from learning about it because reason, correctly used, always supports the Christian faith and sound theological reflection.

In his Metaphysics, Aristotle asks some interesting questions which center around the ultimate nature of reality. He explores the nature and attributes that particular things have and seeks to understand their individual being in light of the unity of all reality (the ancient question of the one and many, again). Investigating particular things, however, can only get one so far which is why Aristotle does not stop with ontology”1 Aristotle understands that science has its own intrinsic limitations. Science is inherently limited because it can answer questions only about one particular aspect of reality. If science tries to go beyond its particular field of individual things and explore all reality in order to make sense of existence as a unified whole, it is no longer doing physical science, but metaphysics. According to Aristotle, if there is a science above and beyond the individual physical sciences, it must be the investigation of metaphysics, first philosophy, the study of being as being.

Aristotle explains why in this passage from his Metaphysics:

For one might raise the question whether first philosophy is universal, or deals with one genus, i.e., some one kind of being; for not even the mathematical sciences are all alike with a certain particular kind of thing, while universal mathematics applies alike to all. We answer that if there is no substance other than those which are formed by nature, natural science will be the first science; but if there is an immovable substance, the science of this must be prior and must be first philosophy, and universal in this way, because it is first. And it will belong to this to consider being qua being—both what it is and the attributes which belong to it qua being. (548)

Aristotle believes there must be an “immovable substance” which provides the foundation for all reality. For Aristotle, being and substance are synonymous and the Metaphysics is an attempt to discover the ultimate foundations of being (of course, ‘being’ and ‘substance’ are understood in different senses and we will get that below). If there really is such an ultimate being, then the study and knowledge of that being would be called first philosophy because knowledge of that kind of being would be truly universal and foundational. It would be the ground of all being.

Now, substance, or being, is an important category for Aristotle, and it takes some work to understand his meaning. For Aristotle, that which underlies a thing primarily is thought to be in its truest sense its substance. That is why he can say that the soul is the substance of an animal or human, and that matter is the substance of tree or rock (see his Metaphysics, book VII, chap. 3)2. Aristotle believes there must be an immovable perfect substance and first cause of all reality.

For Aristotle, it is important that theology belongs to the science of “first things” or the science which investigates the first principles and causes of reality. For Aristotle, there must be basic first principles of reality and theology must be field which devotes itself to this particular kind of study. Part of theology is to study being as being. Aristotle explains,

We are seeking the first principles and the causes of the things that are, and obviously of them qua being. For, while there is a cause of health and of good condition, and the objects of mathematics have first principles and elements and causes, and in general every science which is ratiocinative or at all involves reasoning deals with causes and principles, more or less precise, all these sciences mark off some particular being—some genus, and inquire into this, but not into being simply nor qua being, nor do they offer any discussion of the essence of the thing of which they treat. (547)

Aristotle believes that there must be a science which investigates the first principles of all reality. Other fields investigate a small portion of reality. Metaphysics and theology investigate the possibility of transcendent and divine things. If there is a God, then, that would be a significant part of the investigation, because such a being would account for reality and being as whole. Aristotle, of course, does believe in a divine being, immovable substance, a first cause of reality. In other words, Aristotle believes that the idea of God is of first importance, the first principle of reality. He considered God among the first principles of metaphysics. That is why he calls metaphysics, “theology.”

Aristotle puts a finer point on this:

For the most divine science is also most honourable; and this science alone must be in two ways, most divine. For the science which it would be most meet for God to have is a divine science, and so is any science that deals with divine objects; and this science alone has both these qualities for (1) God is thought to be among the causes of all things and to be a first principle, and (2) such a science either God alone can have, or God above all others. All the sciences, indeed, are more necessary than this, but none better (501).

Analogously, we are now in a position to see how Aristotle’s foundational ideas of metaphysics and theology are entirely reconcilable with the Western Judeo-Christian understanding of God. “Being” or “the ground of being” is the most proper name for God. We already discovered in our last post, the most important verses in all of Christian metaphysics–God’s self-revelation as the “I Am” or one-who-who-causes-to-be in Exodus 3:14 and is confirmed throughout both testaments. For example, Christ, the second member of the trinity, says “I am the light of the world” (John 9:5), and in Mark 14:62, “I am,” said Jesus. “And you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven.” And of course, God’s self-disclosure in Revalation 1:17 “I am the first and the last.” These “I am” sayings found in the Christian Bible indicate that God is the ground of being. Dr. Mortimer Adler claims that ‘being’ used in this theological context, “becomes the richest of terms—the one which has the greatest amplitude of meaning” (101).

At this point, it is important to note that Aristotle was not always correct in his understanding of theology and God. Christians understand that God is not a distant being that can only think about himself (Aristotle believes that the divine nature was reason or thought thinking about itself). Classical Christians understand that God not only created this world but sustains it, and while transcendent, nevertheless is intimately involved with reality and his creatures. Furthermore, Aristotle’s theology has largely been outpaced by Augustine, Boethius, Anselm, Aquinas, and others. But it is also important to keep in mind that Christians should have some respect and gratitude for the work of Aristotle. He did lay the overall metaphysical foundation which is still used today. Once understood, we can see how Aristotle set up the entire metaphysical foundation for theology. Aristotle understands that being can not come from non-being and that there must be something like the principle of causality—that everything that comes into being is caused, or comes into being by virtue of something outside itself—at work (much of his work is dedicated to understanding the nature of cause). Aristotle is correct about these first principles and lot more. We should remember the words of Augustine when he said that we should claim and use that which is in harmony with our faith.

Works cited

Adler, Mortimer. Great Books of the Western World. Vol. 1. Chicago: Encyclopedia Britannica, Inc., 1996. S.V. Being

Augustine. Great Books of the Western World. Vol. 16. Chicago: Encyclopedia Britannica, Inc., 1996.

Aristotle. Great Books of the Western World. Vol. 7. Chicago: Encyclopedia Britannica, Inc., 1996.

For Further Reading

A. E. Tayler, Aristotle (Dover, 1955).

Henry Veatch, Aristotle: A Contemporary Appreciation (Indiana University Press, 1974)

Mortimer Adler, Aristotle For Everybody: Difficult Thought Made Easy (Touchstone, 1978)

1 Ontology is the branch of metaphysics concerned with the nature and relations of being (or reality). In particular, ontology is concerned with the nature of being, the kinds of things that have existence, and the properties, characteristics, and qualities of particular things. When one asks “What is the ontology of time or energy?” the question is about the properties and characteristics of time or energy. When one asks about the ontology of God, one is asking about what kind of being God is and what kind of qualities or attributes he has.

2For Aristotle, form and substance combine to make matter. He does explain, however, that ‘substance’, like ‘being’ can be discussed in different ways or senses of meaning and refer to one thing – what Aristotle calls “pros hens,” or in relation to one. As Aristotle explains, “It follows, then, that ‘substance’ has two senses, (A) the ultimate substratum, which is no longer predicated of anything else, and (B) that which, being a ‘this’, is also separable—and of this nature is the shape or form of each thing” (538). He further elaborates “For that which underlies a thing primarily is thought to be in the truest sense its substance. And in one sense matter is said to be of the nature of substratum, in another, shape, and in a third, the compound of these” (551).