Does God Exist? (2002)
Opening Statement by Imran Aijaz
I would like to thank Richard Carrier for making this internet debate possible, and for agreeing to moderate the exchange between Dr. Bill Cooke and myself. I would also like to thank Dr. Cooke for agreeing to participate with me in addressing the important question of God's existence.
Opening Arguments For Theism
Theism, classically understood, is the contention that there exists a God. Minimally understood, the term "God" refers to a supernatural being - the personal creator and sustainer of our universe. This generic understanding is shared by Judaism, Christianity and Islam, among other belief systems. There are many good reasons, I believe, for thinking that God - a personal creator and sustainer of the universe - exists, but due to the word limitations of this debate, I will restrict myself to sketching out a three-step theistic argument, based on cosmological and teleological considerations, in favour of theism.
I. The Prima Causa
First, I shall argue for the ontological necessity of a first cause of the cosmos. Consider the fact that there are countless contingent entities in the world around us: humans, animals, rocks, trees, stars and so on. And these, as no man will deny, were brought (productively) into existence by various efficient causes. For example, the existence of raindrops falling from the sky is brought about by clouds. Clouds too are contingent, and therefore, have an efficient cause that brings them about, viz., the condensation of water vapour in the atmosphere into water droplets. Thus begins the causal regress: a chain of contingent causes that will either (i) progress ad infinitum or (ii) have a non-contingent first cause as its terminus. The latter is the more reasonable contention. Here, I follow William Lane Craig in defending the now famous Kalam cosmological argument  that can be presented in syllogistic form as follows:
1. Whatever begins to exist has a cause of its existence.
2. The universe began to exist.
3. Therefore, the universe has a cause of its existence.
Premise (1) is the well known causal principle founded on the metaphysical truth of ex nihilo nihil fit ("from nothing nothing comes"). Although (1) is not a logically necessary truth, I still believe it has an extremely high epistemic status.
There are usually three basic reasons for rejecting a premise: (a) it is demonstrably false, (b) it lacks sufficient evidence or (c) it has at least one counterexample. If Dr. Cooke wishes to dispute (1) then he must categorize the causal principle into one of the three classifications I have stated. For many, the premise is grasped intuitively. Thus, David Hume's famous remark that he "never asserted so absurd a Proposition as that anything might arise without cause." 
Next comes premise (2). Could the universe be eternal? Is it not possible that an infinite causal sequence of contingent entities preceded the present moment? There are good reasons to think not. If the sequence of events preceding the present moment is infinite, then it follows that we are currently at the end of an infinite sequence of events (a trivial, but important point). Against this supposition, two arguments can be proffered.
First, if we are at the end of an infinite causal sequence, then it follows we have a set that is actually infinite, denoted by the mathematical symbol À0. Such a set, however, is prone to all the paradoxes of the infinite and is therefore rendered implausible. Second, the supposition that we are at the end of an infinite causal sequence is refuted by the clear fact that a beginningless sequence can never be completed, or traversed. It would never be possible, for example, for a man to reach the last rung of a ladder that consists of an infinite number of rungs. The fact that the sequence of events in the world does have a terminus (i.e. the present moment) falsifies the possibility of an infinite regress into the past.
Therefore, we are led to reject the possibility of a completed infinite sequence of events because its implications are openly false. Once again, according to David Hume: "[a]n infinite number of real parts of time, passing in succession, and exhausted one after another, appears so evident a contradiction, that no man whose judgment is not corrupted, instead of being improved, by the sciences, would ever be able to admit of it."  A similar verdict is given later by Immanuel Kant. Now if the possibility of an infinite causal sequence preceding the present moment is false, it is true that the causal chain must be finite, and it follows ipso facto that the universe had a beginning. This conclusion is, of course, supported by modern Big Bang cosmology which postulates an origin for our cosmos some 10 to 20 billion years ago.
Given the truth of premises (1) and (2) it follows deductively that the universe has a metaphysical cause for its existence: the first cause.
II. The Personal Creator
The foregoing considerations give us good reasons to believe in a first cause of the cosmos. But the argument for God's existence is still incomplete, for as William Rowe complains, "[w]hy must a first efficient cause or a necessary being have the properties of the theistic God?" One of the main properties of the theistic God is that He is personal, and if it could be shown that the first cause is personal, then we would have a good response to Rowe's objection (along with the considerations in section III below). Here, the following argument can be presented:
1. The first cause is either personal or mechanical.
2. The first cause is not mechanical.
3. Therefore, the first cause is personal.
We can affirm the truth of (2) based on the fact that the first cause is eternal, yet it gave rise to a temporal event (i.e. the beginning of the universe). The reason for thinking that the first cause is personal is because a first cause requires a will, since an unthinking mechanical cause requires antecedent causal influences to occur. But this cannot be, for we know that the first cause is the first productive cause in the causal nexus. Only something that controls its own actions can be the first cause; the sufficient reasons for its actions are found within itself. This, of course, occurs all the time when free-willed agents choose a particular course of action, such as my deciding to go for a walk, for example.
The argument can be pressed further. If the first cause simply consisted of a set of necessary and sufficient conditions that existed from eternity, then the effect would also have existed from eternity (i.e. the universe should have been eternal). For example, if the necessary and sufficient conditions for the existence of fire are present, then the effect--a flame--arises immediately. There is no delay from cause to effect. Thus, if the necessary and sufficient (causal) conditions for fire are present from eternity, then a flame would also exist (as an effect) from eternity. What this analysis reveals is that the origin of our temporal universe (which began a finite time ago) could not have resulted from a mechanistic state of affairs that existed from eternity. As Craig argues, "[t]he only way to have an eternal cause but a temporal effect would seem to be if the cause is a personal agent who freely chooses to create an effect in time." 
At this point, not only do we have powerful reasons to believe in a first cause of the universe, but also, to think of this cause as a personal and transcendent Creator. It seems that this cause is also enormously powerful (if not omnipotent) and intelligent (if not omniscient) based on the fact that it brought a complex, ordered and fine-tuned universe, such as ours, into existence.
III. An Intelligent God
Further evidence that the Creator of our universe is a conscious and intelligent being comes from the complexity, order and fine-tuning of our cosmos. In his paper The Unreasonable Effectiveness of Science, Paul Davies argues that scientific explanations are only made possible by the fact that our universe is ordered by various laws of nature. These are not just any set of possible laws, but have numerous features to suggest "that our existence is linked into the laws of the universe at the most basic level." He takes this as "powerful evidence that the universe exists for a purpose."
The fact that nearly everything about the structure of the universe - its fundamental laws and parameters - is balanced on a razor's edge to allow the evolution of life to occur is an extremely persuasive argument for theism. It can be formulated as follows:
1. A universe exhibiting fine tuning is not improbable under the theistic hypothesis.
2. A universe exhibiting fine tuning is very improbable under the atheistic hypothesis.
3. Therefore, a universe exhibiting fine-tuning is evidence for theism over atheism.
Three examples of fine-tuning, among dozens more, are as follows:
The initial explosion of the Big Bang required a rate of expansion that could not have differed in strength by more than 1/1060, otherwise, the universe would not have been able to form life.
The strong nuclear force (which brings protons and neutrons together) could not have been stronger or weaker than 5%, otherwise, life would not occur.
Gravity could not have been stronger or weaker than 1/1040, otherwise, stars which sustain life (such as the sun) could not exist.
Whatever one makes of such probability calculations, it is fairly clear that the universe requires fine-tuning of various parameters (out of an infinite number of possible combinations) to permit the evolution of life, and only a specific and restricted combination of these parameters will allow life to evolve.
Let us now turn to the argument sketched out above.
Premise (1) is relatively non-controversial, since, according to theism, God created the material universe, and designed it to allow the evolution of intelligent life to occur. The existence of fine-tuning, then, is hardly surprising given the truth of theism. What about (2)? This seems to be true based on the consideration that there is no intentionality behind the cosmos on the atheistic worldview. So not only must one adopt the view that the universe began to exist uncaused, if one is to follow someone like Quentin Smith, but that it came into existence fortuitously with the right conditions to permit life.
The now famous "firing-squad" analogy illustrates the point well. If 50 sharp shooters all fire at me, and I emerge unscathed, I seek a plausible explanation which is not to be found in the retort, as John Leslie correctly notes, that "if they had not missed me I wouldn't be here to consider the fact." This response simply begs the question as to why this happened, given the fact that my survival was extremely improbable. It is far more likely that there was intentionality behind my survival (all the sharpshooters conspired to miss) rather than the unlikely suggestion that they all missed by chance.
Therefore, if premises (1) and (2) are true, it follows that the existence of fine-tuning in the universe gives credibility to the theistic hypothesis over the atheistic one.
My arguments, if sound, show the necessity of a first cause of the universe. The temporality of the universe gives us good reasons for thinking this cause is personal, and the argument from fine-tuning adds further weight to the contention that the first cause is a personal, powerful and intelligent being. Therefore, I submit to Dr. Cooke that my three-step argument gives us good reasons for thinking that God exists.
 See William Lane Craig, The Kalam Cosmological Argument, (London, Macmillan: 1979); also: The Existence of God and the Beginning of the Universe (www.leaderu.com).
 David Hume to John Stewart, February, 1754, in The Letters of David Hume, J. Y. T. Greig, (ed.), (Oxford, Clarendon Press: 1932), 1:187.
 Craig, "The Existence of God and the Beginning of the Universe" (www.leaderu.com).
 Paul Davies, "The Unreasonable Effectiveness of Science," in John Marks Templeton, (ed.), Evidence of Purpose: Scientists Discover a Creator, (NY, Continuum: 1996).
 Paul Davies, Superforce: The Search for a Grand Unified Theory of Nature, (NY: Simon and Schuster: 1984), p. 242.
 John Leslie, "How to Draw Conclusions From a Fine-Tuned Cosmos" in Robert Russell, et. al., (eds.), Physics, Philosophy and Theology: A Common Quest for Understanding, (Vatican Observatory Press: 1988), p. 304.