Neither do I confess God’s existence on the basis of the empirical or inductive arguments of methodological natural theology. Following Aristotle’s lead, Thomas Aquinas set forth his famous “five Ways” in his Summa theologica, I, 2, 3, and Summa contra Gentiles, I, XIII. By it he attempted to demonstrate from sense data alone without any a priori equipment the existence of God. For the following reasons his arguments are invalid:
1. One simply cannot begin with the existence of sensory data and proceed by formal laws of logic to the existence of a nonsensory conclusion.
2. Aquinas believed that the mind, prior to sense impressions, is a tabula rasa, a blank slate. But a tabula rasa epistemology is freighted with insur-mountable obstacles to the build-up of knowledge, for if all the mind has to work with are sense-perceptions as reports of what is going on in the external world, knowledge can never rise to the universal and the necessary since from flux only flux can come. In other words, Aquinas’s denial of innate ideas of God or of anything else makes the build-up of knowledge impossible.
3. In order to arrive at a first unmoved mover, Aquinas argues that the series of things moved by other things in motion cannot regress to infinity since such a regress would rule out a first mover. Of course an infinite series of moving causes is inconsistent with a first unmoved mover, but if the argument is designed to demonstrate the existence of the latter, the latter’s existence cannot be used ahead of time as one of the premises in the argument. This is a blatant “assertion of the consequence.”
4. Aquinas’s arguments require that the universe as a whole be an effect. But no one has ever seen the universe as a whole, and no observation of the observed parts of the universe gives this necessary assumption. There is no demonstrable reason why the universe as a whole might not be made up of interdependent contingencies which, operating together, sustain and support each other.
5. Because Aquinas was convinced that nothing can be predicated of creation in the same sense that it is predicated of God, when he argues from the “existence” of the world to the “existence” of God, he uses the word existence in two different senses and thereby commits the logical fallacy of equivocation.
6. Granting, for the sake of argument, the validity of the cause and effect relationship, if it is valid to conclude from observed effects the existence of their cause(s), it is not valid to ascribe to their cause(s) any properties beyond those necessary to produce them. All the existence of a finite world would demand is the existence of a finite cause sufficiently powerful to cause it, a far cry from the omnipotent Creator of the Bible. Moreover, since much of what one observes involves what Christians call moral evil, a strict application of the cause and effect relation would require the conclusion that the ultimate cause of these effects is not completely morally good.
7. Granting, again for the sake of argument, that Aquinas demonstrated from motion the existence of an unmoved mover, yet when he adds, “And everyone understands this to be God,” we may demur. The argument taken at face value would prove the existence merely of an unmoved cause of physical motion. But such a mover has no qualities of transcendent personality. It is highly significant that the terms Aquinas employs to denote the God he believes he arrives at by this method are all neuter: ens perfectissimum, primum movens, etc. In other words, if his arguments were valid, since there is nothing transcendent or supernatural about Aquinas’s first cause, they would be destructive of Christianity with its infinite, personal God.
All of the empirical arguments of natural theology (construed methodologically) for God’s existence may be reduced to the cosmological argument or variations of it. This argument assumes at least five things which should not and cannot be assumed but rather must be demonstrated if the argument is to be accepted:
1. the validity of the epistemological theory of empiricism;
2. an empirical criterion to screen out unwanted sense data;
3. the “effect” character of the universe;
4. the validity of the cause and effect relationship; and
5. the impossibility of an infinite causal regress.
To validate and demonstrate these matters (and there are many other issues that would have to be addressed along the way) will require the Christian’s engagement in endless and intricate argumentation which if wrong at any single point in his chain of reasoning nullifies his entire intellectual enterprise. I will explain.