July 11, 2013
Kant’s Critique of the Traditional Arguments for the Existence of God
This is a summary of the presentation given on the 4th of July. Unfortunately we were not able to video record the meeting. However, there were power point slides (see Kants Critique).
1 Kant for Dummies
When I was a young engineer, a senior manager at the Electricity Trust told me, “If you really understand something, then you can explain it simply”. I believe this is largely true. So, I am going to attempt to provide a simple explanation of Kant’s Critique of the traditional arguments for the existence of God. Unfortunately the converse does not apply. If you explain something simply, this does not necessarily mean that you really understand. Anyway, here we go.
After reading Kant’s Critique of Pure Reason, the German Lutheran Pietist J. G. Hamann wrote “If it is fools who say in their heart there is no God, those who try to prove his existence seem to me to be even more foolish.” However, are Kant’s arguments correct and was Hamann right in his assessment? In fact, Kant’s arguments have not been universally accepted. So, at the risk of being a fool, I will reconsider Kant’s arguments and assess whether it is sound and valid to argue for the existence of God.
So, what were his arguments, are they valid, are they relevant to contemporary arguments and how do they affect the scope and usefulness of arguments for the existence of God?
1.1 Immanuel Kant
Immanuel Kant (1724-1804) was a major philosopher during the period of the Enlightenment, which is a supposedly anti-Christian movement. However, Kant is not necessarily anti-Christian. He was brought up in a devout Lutheran family and never rejected that faith. Although he is famous for having launched a critique against the traditional arguments for the existence of God, he still believed in God. In fact he believed that atheism was dangerous to society and also developed an argument for the existence of God based on morality as outlined in his Critique of Practical Reason. Thus we can consider Kant’s critique as “friendly fire”. His intent was to clarify the limitations of the traditional arguments so that their claims were not overstated.
During the Enlightenment the 2 major epistemological movements were rationalism and empiricism. The chief originator of empiricism was John Locke, who believed that all of our knowledge came through the senses. Rene Descartes was the father of rationalism. Descartes’ aim was to gain certain knowledge from a foundation of indubitable beliefs and to derive certain conclusions from that foundation using “Pure Reason”.
1.2 Critique of Pure Reason
Kant’s major work was the Critique of Pure Reason (1787). Kant was primarily an empiricist and his critique was an attempt to unite empiricism with rationalism, which he referred to as Pure Reason. In this work Kant also provided a critique of the traditional arguments for the existence of God. Kant’s critique has been highly influential.
Kant’s analysis of the arguments for the existence of God are contained in Transcendental Doctrine of Elements, Second Part, Second Division, Book 2, chapter 3, sections 3 to 7 of the Critique of Pure Reason.
2 Definitions of Terms
Before we review the traditional arguments we should be careful to define out terms, especially regarding existence. At least 3 types of existence have been identified. These are:
- Impossible existence
- Contingent existence and
- Necessary existence.
Impossible existence refers to entities that cannot exist. These are usually entities that are logically impossible, such as square circles and married bachelors.
Contingent objects are those that we typically observe. They have a beginning, they are caused and we can imagine a world in which they do not exist. In other words they do not have to exist.
When we talk about God it is generally assumed that God is a Necessary Being. This may come in a number of flavours. It may mean that he is uncaused or has no beginning and is the cause of all other things. However, there is an even stronger sense. It may also mean that he exists necessarily. In other words it is impossible for God not to exist and that he must exist in all possible worlds. However, when we say that God is eternal and uncaused, are we necessarily asserting that God is necessary in this last and strongest sense?
Let us keep this in mind as we review Kant’s objections.
3 The Traditional Arguments for Existence of God
According to Kant (1787), there are only 3 arguments that need be considered. These are the Teleological (Design), Cosmological (First Cause) and Ontological arguments. “More there are not, and more there cannot be.” Why is this so? He does not say, but let’s just see what he says.
The Cosmological and Teleological arguments have been around since Plato and Aristotle. They depend on observations about the actual world and even have some basis in scripture, since Paul claims that God’s eternal power and divine nature is clearly perceived in what he has made.
The Ontological Argument, however, is of a quite different nature. It was invented much later in the 11th century. Nobody had thought of it before. It is nearly a purely logical argument with no reference to any particular thing in the actual world, except perhaps our minds.
Although the Cosmological and Design Arguments are much older than the Ontological Argument, Kant considers the Ontological Argument first. He argues that the Ontological Argument is a poor argument. He then argues that the other 2 arguments are ultimately dependent on the Ontological Argument and thus fall with it.
Thus firstly we will consider the Ontological Argument.
4 Ontological Argument
We have already considered the Ontological Argument 4 weeks ago (see http://reasonablefaithadelaide.org.au/the-ontological-argument/). However, I will give an overview. This will be an introduction for those who were not present at that meeting and some revision for those who were. I will provide an overview of the historical development of the Ontological Argument prior to Kant. This will cover Anselm, Gaunilo and Descartes. I will then summarise Kant’s Objections to the Ontological Argument, then compare modern Ontological Arguments and then give assessment of the relevance of Kant’s critique.
The Ontological Argument was first developed by a Benedictine monk called Anselm (1033-1109), who later became Archbishop of Canterbury. The Ontological Argument is contained in the Proslogion, which means “discourse on the existence of God”. Even if his argument is not correct, it really is a stunning piece of original thinking.
Psalm 14 states that “The fool says in his heart ‘There is no God’”. Anselm alludes to this passage and argues that even a fool has a concept of God. He states,
Hence, even the fool is convinced that something exists in the understanding, at least, than which nothing greater can be conceived. For, when he hears of this, he understands it. And whatever is understood, exists in the understanding. And assuredly that, than which nothing greater can be conceived, cannot exist in the understanding alone. For, suppose it exists in the understanding alone: then it can be conceived to exist in reality; which is greater. Therefore, if that, than which nothing greater can be conceived, exists in the understanding alone, the very being, than which nothing greater can be conceived, is one, than which a greater can be conceived. But obviously this is impossible. Hence, there is no doubt that there exists a being than which nothing greater can be conceived, and it exists both in the understanding and in reality.
This passage is quite verbose, but we can simplify it a bit. Anselm reasoned that, if “that than which nothing greater can be conceived” existed only in the intellect, then it would not be “that than which nothing greater can be conceived”, since it can be thought to exist in reality, which is greater. Thus it follows that “that than which nothing greater can be conceived” must exist in reality.
Alvin Plantinga has provided a summary of Anselm’s argument in a more logical form:
- God is defined as the greatest conceivable being
- To exist is greater than to not exist
- If God does not exist then we can conceive of a greater being that does exist
- Thus if God does not exist then he is not the greatest conceivable being
- This leads to a contradiction
- Therefore God must exist
4.2 Gaunilo of Marmoutiers
In Anselm’s own time, his argument was opposed by Gaunilo of Marmoutiers. He parodied the argument by applying it to other entities, such as “A greatest conceivable island” or “a greatest conceivable lion”. This tactic has often been used to parody the ontological argument. However, this was not the approach taken by Immanuel Kant.
The Ontological Argument was developed further by philosophers such as Descartes, Spinoza and Leibniz.
Descartes’ simplified argument can be summarised as:
- The very conception of God includes the possession of all perfections.
- Existence is a perfection.
- Therefore, it is inconceivable that God does not exist.
4.4 Kant’s Ontological Argument Objections
It is difficult to summarise Kant’s critique of the Ontological Argument simply. However, it seems that Kant is mainly targeting Descartes’ version, although he does not make this clear. The major points that he seems to be raising are.
- The Ontological Argument confuses existence and essence
- Existence is not a Predicate
- Negation of the proposition “God exists” does not result in a contradiction
- You cannot establish God’s existence merely from our conceptions of God
Kant’s critique of the Ontological Argument has not gone unchallenged. For each of Kant’s objections, I will mention counter objections that have been raised.
4.4.1 Confusing Existence and Essence
Descartes’ version of the Ontological Argument can be summarised as
- The very conception of God includes the possession of all perfections.
- Existence is a perfection.
- Therefore, it is inconceivable that God does not exist.
Descartes claims that existence is a perfection. However, Kant believes that Decartes is confusing essence with existence. The essence of God answers the question, “What is God like?” and describes God’s properties or characteristics, such as omniscience. However, the existence of God answers the question, “Does God exist?” Essence and existence are 2 different things. When Descartes claims that existence is a perfection, he is confusing or conflating essence with existence. On this issue Kant may well be right.
4.4.2 Existence is Not a Predicate
Kant’s main critique of Anselm’s and Descartes’ version of the Ontological Argument is that existence is not a predicate. Propositions consist of a subject and a predicate. For instance, in the sentence “A dog has four legs”, the dog is the subject and “has four legs” is the predicate. The predicate describes properties of the subject. By claiming that existence is not a predicate, Kant is challenging the claim that existence is a perfection, or that to exist is greater than to not exist.
4.4.3 Negation is not a Contradiction
Kant claims that “God exists” is not a necessary truth. Some statements are necessarily true, since their negation entails a contradiction. A couple of examples are:
- All bachelors are unmarried
- All squares have 4 sides
If we negate the predicate we get a contradiction, eg
- All bachelors are married
- All squares do not have 4 sides
However, consider the statement “God exists”. If we negate the predicate we get “God does not exist”. However “God does not exist” is a coherent statement that does not entail a contradiction. Thus Kant argues that “God exists” is not a necessary truth. In this respect I think Kant is right. The statement “God exists” is not a necessary truth. However, I think Kant confuses “necessary truth” with “Necessary Being”. The Ontological Argument is not arguing that “God exists” is a necessary truth. It is arguing that God exists necessarily, and that is different.
4.4.4 Conceptual Conundrum
Anselm argues for concepts in our minds to the objective existence of God. However, Kant argues that we cannot establish God’s existence merely from our conceptions of God. How can a conceptual conundrum in the mind affect a being’s objective existence?
4.4.5 Kant’s Conclusion
Thus Kant concludes his discussion with the cutting assessment that the Ontological Argument “neither satisfies the healthy common sense of humanity, nor sustains the scientific examination of the philosopher.”
This all sounds very damning, but are Kant’s objections valid?
Kant claims that he is targeting Ontological arguments in general, but he seems to be mainly targeting Descartes’ version rather than Anselm’s.
4.5 Response to Kant’s Ontological Argument Objections
Two objections to Kant’s critique of the Ontological Argument are that
- His Predicate Argument is irrelevant, and that
- Necessary Existence is indeed a Property
4.5.1 Predicate Argument is Irrelevant
Kant’s most famous objection to the Ontological Argument is his claim that existence is not a predicate. However, even this has been challenged by eminent philosophers. Alvin Plantinga has claimed that Kant’s predicate argument is irrelevant to Anselm’s Ontological Argument.
Kant’s point, then, is that one cannot define things into existence because existence is not a real property or predicate in the explained sense. If this is what he means, he’s certainly right. But is it relevant to the ontological argument? Couldn’t Anselm thank Kant for this interesting point and proceed merrily on his way? Where did he try to define God into being by adding existence to a list of properties that defined some concept? …If this were Anselm’s procedure … then indeed his argument would be subject to the Kantian criticism. But he didn’t, and it isn’t. The usual criticisms of Anselm’s argument, then, leave much to be desired. Of course, this doesn’t mean that the argument is successful, but it does mean that we shall have to take an independent look at it.
Plantinga’s counter objections are not universally accepted (Robson 2012). However, they do illustrate that Kant’s predicate critique of Anselm’s version of the Ontological Argument is not universally considered to be watertight.
4.5.2 Necessary Existence is a Property
One of Kant’s key claims is that existence is not a property and the Ontological Argument fails because it assumes it is. However, he then proceeds to apply this to necessary existence. The idea of necessary existence is not the same thing as the idea of a being whose properties include existence. A being exists necessarily if it is impossible for that being not to exist. This need not involve the inclusion of a property called existence. Necessary existence is a type of existence and hence necessary existence is indeed a property.
4.6 Does it apply to Modern Arguments?
Alvin Plantinga has been critical of Kant’s arguments regarding Anselm’s formulation of the Ontological Argument. However, he has also proposed a revised form of the ontological argument called the Modal Ontological Argument, which goes as follows:
- It is possible that a Maximally Great Being exists
- If it is possible that a Maximally Great Being exists, then a Maximally Great Being exists in some possible world
- If a Maximally Great Being exists in some possible world, then a Maximally Great Being exists in every possible world
- If a Maximally Great Being exists in every possible world then a Maximally Great Being exists in the actual world
- Therefore a Maximally Great Being exists
Plantinga believes that his argument avoids Kant’s fire. He claims:
Now we no longer need the supposition that necessary existence is a perfection; for obviously a being can’t be omnipotent (or for that matter omniscient or morally perfect) in a given world unless it exists in that world… It follows that there actually exists a being that is omnipotent, omniscient, and morally perfect; this being, furthermore, exists and has these qualities in every other world as well.
However, Plantinga concedes:
But obviously this isn’t a proof; no one who didn’t already accept the conclusion, would accept the first premise. The ontological argument we’ve been examining isn’t just like this one, of course, but it must be conceded that not everyone who understands and reflects on its central premise — that the existence of a maximally great being is possible — will accept it. Still, it is evident, I think, that there is nothing contrary to reason or irrational in accepting this premise. What I claim for this argument, therefore, is that it establishes, not the truth of theism, but its rational acceptability. And hence it accomplishes at least one of the aims of the tradition of natural theology.
4.7 The Essence of the Ontological Argument
To me the essence of the Ontological Argument is that if it is possible that a Necessary Being exists, then a Necessary Being must exist in all possible worlds. This seems quite logical. However, the following issues still need to be resolved:
- Is a Necessary Being possible?
- Can we show that the Necessary Being is maximally perfect and is God?
4.8 Conclusion on the Ontological Argument
There seems to be an essential difference between Anselm’s version of the Ontological Argument and Plantinga’s. Anselm seems to be arguing that it is impossible for God not to exist, whereas Plantinga is arguing that if it is possible for God to exist, then he must exist. However, he leaves the possibility of God’s existence as an open issue that people will debate. Thus Plantinga concludes that it is rational to believe in God but the Modal Ontological Argument is not a proof.
Personally I am not convinced by either Anselm’s or Decartes’ version of the Ontological Argument and so I am not overly perturbed by Kant’s critique. However, I am more interested in his critique of the Cosmological argument. Has Kant undermined the Cosmological Argument in all of its possible forms?
At first sight it seems strange that Kant can possibly claim that the Cosmological Argument and Design Argument are dependent on the Ontological Argument. After all the Cosmological Argument and Design Argument have been around for over a thousand years before the Ontological Argument was ever thought of (or conceived – pun intended).
However, Kant believes that the cosmological and design proofs presuppose the ontological proof since these proofs conclude that a Necessary Being must be a most real or most excellent being. Thus even if the Cosmological Argument or Design Argument can show that a Necessary Being must exist, they then rely on the Ontological Argument to show that the Necessary Being is God.
Kant then argued that the Cosmological Argument is dependent on the Ontological Argument. Thus he believes that, if the Ontological Argument fails, the Cosmological Argument and the Design Argument fall with it.
Firstly we will consider the Cosmological Argument.
5 Cosmological Argument
Kant’s main attack on the Cosmological Argument is that it is dependent on the Ontological Argument. The Ontological Argument argues God is a Necessary Being. Kant claims that the Cosmological Argument argues for the existence of a Necessary Being, which it then identifies as God. Kant accepts that there must be a Necessary Being in order to avoid an infinite regress. However, he disputes that it can be proven that the Necessary Being is God. He believes that the Cosmological Argument relies on the Ontological Argument to make that association. Thus if the Ontological Argument fails then the Cosmological Argument falls with it. However, is Kant right about this dependency?
5.1 Dependency Arguments
Kant seems to use 3 arguments to show the dependency of the Cosmological Argument on the Ontological Argument.
Kant’s key arguments for making the Cosmological Argument dependent on the Ontological Argument are that the Cosmological Argument assumes that:
- a Necessary Being is Possible
- the Necessary Being is Actual
- the Necessary is God
5.1.1 Necessary Existence is Possible
Firstly the Cosmological Argument seems to presuppose that necessary existence is possible and then shows that it is actual, since if it is not possible then it cannot be actual. Kant’s argument goes something like this:
- The concept of a Necessary Being appears in both arguments.
- The Cosmological Argument assumes that necessary existence is at least possible since if it is not possible it cannot be actual.
- This is a conclusion of the Ontological Argument.
- Thus the Cosmological Argument is dependent on the Ontological Argument.
However, the Cosmological Argument does not assume that necessary existence is possible. Instead, the argument tries to show that necessary existence is actual, from which we can infer that it must be possible. This practice is currently used in science. Cosmologists have proposed the existence of Dark Matter and Dark Energy to explain the motion of galaxies. They have little idea what they are and so cannot directly prove that they are possible. However since they are actual, they must be possible.
5.1.2 The Necessary Being is God
The second reason that Kant provides for the dependency of the Cosmological Argument on the Ontological Argument is that the Cosmological Argument relies on the Ontological Argument to associate the Necessary Being with God. Kant claims that the Ontological Argument shows that God is a Necessary Being and therefore exists. The Cosmological Argument shows that a Necessary Being exists, but then relies on the Ontological Argument to infer that the Necessary Being is God.
However, this is not necessarily so. William Lane Craig’s Kalam Cosmological Argument does not go via this route. We will discuss the Kalam Cosmological Argument later.
5.2 Additional Objections
As well as claiming that the Cosmological Argument is dependent on the Ontological Argument, Kant raises additional objections to the Cosmological Argument itself.
Kant thinks that space and time are absolutely necessary and are examples of some things that are necessarily existent apart from God. However, Kant’s views are simply dated and have been overtaken by recent scientific discoveries.
One of Kant’s aims was to define appropriate limits for the exercise of pure reason. He does not disparage pure reason altogether as much of his critique is pure reason. However, his belief that space and time were infinite and existed independently of God was, he believed, a valid conclusion based on pure reason. It was this belief that caused him to claim that a finite past led to contradictions. However, it appears he was wrong. Later empirical evidence has led to the conclusion that space and time are finite, which means that there is no contradiction if the universe has a finite past. In this case, it seems that Kant has overstepped the use of pure reason, which probably illustrates his point.
5.3 Kalam Cosmological Argument
William Lane Craig is a current proponent of the Kalam Cosmological Argument.
I will cover:
- The argument
- Justifying the premises
- The conclusions drawn
5.3.1 The Argument
Craig’s formulation of the Kalam Cosmological Argument can be summarised by the following syllogism (2008):
- Everything that begins to exist has a cause.
- The universe began to exist.
- Therefore the universe has a cause.
5.3.2 Justifying the Premises
For the most part, premise 1 is usually accepted as being intuitively obvious. Most of his effort goes into justifying premise 2. Premise 2 is justified using 2 philosophical arguments and 2 arguments from scientific discoveries during the last 100 years, which are:
- Philosophical Arguments
- It is impossible to instantiate an actually infinite set. Thus there cannot be an infinite sequence of causes.
- It is impossible to traverse an infinite sequence of causes.
- Scientific Arguments
- The second law of thermodynamics implies that there cannot be an infinite past.
- The expansion of the universe implies that the universe cannot be past infinite and originated in an event 13.3 billion years ago, referred to as the Big Bang.
5.3.3 Argument Conclusions
Craig then uses information about the Big Bang to derive various attributes of the initial cause. The Big Bang marked the beginning of matter, energy, space and time. Thus the cause must at least be transcendent, timeless and powerful. These attributes are not derived from any a priori argument.
The Kalam Cosmological Argument does not argue that the cause of the universe is a Necessary Being or even God. It limits itself to those properties that are directly implied by the empirical and logical evidence.
6 Design Argument
Kant (1787) says that the Design Argument may demonstrate a designer who modifies the form of matter but not a creator of matter. To demonstrate the existence of a creator, we must rely on the Ontological Argument and the Cosmological Argument, which he regards as spurious. This proof can at most, therefore, demonstrate the existence of an architect of the world, whose efforts are limited by the capabilities of the material with which he works, but not of a creator of the world, to whom all things are subject.
In other words, the Design Argument may still be valid, but it is just limited in scope. However, this is not of serious concern. The aim of the arguments for the existence of God is mainly to establish God’s existence, not to completely define God’s attributes, and if the Design Argument is sound, then it is also decisive. The main challenge to the Design argument came much later with Darwin’s theory of evolution, which provided a naturalistic explanation of design within living creatures. To overcome this, the Design Argument has been revived in the form of the Fine Tuning Argument, which highlights design in the laws of physics, which are not subject to a Darwinian explanation. Craig’s formulation of the Fine Tuning Argument can be summarised by the following syllogism:
- The fine tuning of the initial conditions of the universe and of the constants in the laws of physics are due to law, chance or design.
- They are not due to law or chance.
- Therefore they are due to design.
Craig then uses this syllogism to argue for a designer of the universe.
7 Craig’s arguments
From all of the above arguments it is deduced that God is maximally great, exists necessarily, is transcendent, timeless, powerful and the designer of the universe. The Plantinga version of the Ontological argument is not subject to the critique that existence is a perfection. The Kalam Cosmological Argument and the Fine Tuning Argument do not rely on any support from the Ontological Argument. Thus these arguments are immune from the main thrust of Kant’s critiques. However, these arguments still have limitations. They are arguments, not proofs. An atheist can always choose not to believe the premises, although the intent is to make the atheist pay an intellectual price for doing so. If well presented, they should demonstrate that it is rational and reasonable to believe in God. In addition, these arguments do not specifically point to the Christian God and are used by Jews and Muslims as well. Specifically Christian arguments must rely on evidence from the New Testament.
I personally do not find the Ontological Argument to be particularly compelling, but I do find the Kalam Cosmological Argument and the Fine Tuning Argument to be quite convincing. I believe this has Biblical warrant, “For since the creation of the world God’s invisible qualities – his eternal power and divine nature – have been clearly seen, being understood from what he has made, so that men are without excuse” (Romans 1:20). Here Paul seems to be agreeing with the main thrust of the Cosmological and Design Arguments by saying that the observable world provides compelling evidences for some of the properties of the invisible God. If Paul is correct, then well-constructed Cosmological and Design Arguments should provide reasonable evidence for the existence of God.
8 Conclusion on Validity
Kant was also a man of his own time. He lived during the peak of the Enlightenment and many of his views reflect that influence. For instance, Kant claims that the Cosmological Argument is based on the “spurious transcendental law of causality”. It is not certain whether Kant is deriding the law of causality in general or just the notion of a transcendent cause. However, this statement reflects Hume’s scepticism regarding cause and effect, but should we concur with Kant that the principle of cause and effect is spurious? The Enlightenment project aimed to achieve certainty either by rationalism or empiricism. However, it failed to provide assurance even on the principle of cause and effect. However, this principle is the basis of science and is intuitively accepted to be true. After all, according to Francis Bacon, “science is the study of secondary causes”. Kant’s scepticism should be borne in mind when evaluating his critique of the Cosmological Argument. Kant is working from a standard of rigour and a desire for certainty that most scientists and ordinary people would consider to be unrealistic.
There have been a number of critics that have shown that there are numerous weaknesses in Kant’s arguments. However, his arguments have still been widely accepted, even amongst Christian theologians and apologists. Why is this so? Joyce (1922) provides a possible explanation:
It is not to be denied that ever since Kant’s time an impression has prevailed widely that the old proofs are no longer defensible. Possibly the mere fact that an eminent thinker had ventured to call in question such seemingly irrefutable arguments seemed by itself almost equivalent to a disproof. But another reason also, extrinsic it is true to the merits of the criticism, but none the less effective, operated in favour of this result. During the last century, rationalism, in the form either of naturalism or of idealism, had become strongly entrenched in the great centres of learning. It was only natural that thinkers who had discarded belief in a personal God should applaud Kant’s conclusion, even if they might hesitate to affirm that his criticism of the proofs was in all respects sound. Thus it came about that those who admitted the value of the traditional arguments were regarded as out of date. Often the validity of Kant’s objections is simply taken for granted, and the proofs of God’s existence dismissed without more ado. Even some of the apologists of revealed religion, eager not to be behind the fashion, discard them as untenable.
Probably the strongest point that Kant made was that existence is not a predicate, which (to some degree) undermined the Ontological Argument, as formulated by Anselm and simplified by Descartes. Prior to Kant the arguments were regarded as proofs. One of the themes that came out of the Enlightenment was that this level of certainty is just not possible. On the other hand, I believe that Kant’s arguments on the dependency of the Cosmological Argument and Design arguments on the Ontological Argument are highly dubious.
I believe it is beneficial to be aware of Kant’s arguments and to be careful not to overstate the effectiveness and scope of Craig’s arguments. They are arguments, not proofs. However, people like Craig and Plantinga are well aware of Kant’s critique and their arguments are well crafted to avoid Kant’s fire. I have not seen any debate where Craig has been attacked directly on the basis of Kant’s critique, but occasionally some of Kant’s arguments do reappear without Kant being directly invoked.
Thus, in conclusion, I believe we can thank Kant for his interesting points and then proceed merrily on our way.
Craig, W.L. Reasonable Faith: Christian Truth and Apologetics, 3rd edition, Crossway, Wheaton, Illinois, 2008.
Joyce, G.H., Principles of Natural Theology, Longmans, Green and Co., New York, Toronto, Bombay, Calcutta, and Madras, 1922.
Kant, I. The Critique of Pure Reason, 2nd edition, 1787, translated by J.M.D. Meiklejohn, A Penn State Electronic Classic Series Publication, Pennsylvania State University, 2010.
Koons, R.C. Western Theism, Lecture notes and bibliography from Dr. Koons’ Western Theism course (Phl 356) at the University of Texas at Austin, Spring 1998, http://www.leaderu.com/offices/koons/, in particular Lectures 5&9.
Plantinga, Alvin, God, Freedom and Evil, New York: Harper & Row Publishers, 1974. The pertinent section on the ontological argument is quoted at http://mind.ucsd.edu/syllabi/02-03/01w/readings/plantinga.html.
Robson, Gregory, The Ontological Proof: Kant’s Objections, Plantinga’s Reply, KSO 2012: 122-171, posted August 26, 2012 www.kantstudiesonline.net.
Worthing, M., Apologetics Intensive Lecture Notes, Section 05, Apologetics, proofs and science, 2012.