Theism, Idealism, and Arguments for God
Belief in a Supreme Spiritual Reality is often developed in a philosophically profound way. This is clear in a second development of the basic idea of Spiritual Reality, idealism, which is characteristic of some major Indian traditions. The Supreme Lord is not a separate personal being but the inner nature of all reality, whose nature is consciousness, intelligence, and bliss, conscious union with which is the goal of the religious life.
As in the Hebrew tradition, this view begins with an analysis of the human condition and with the realization that there is something deeply unsatisfying about the way most humans live. For Hebrews, this was seen as "slavery to sin," a sort of rebellion against goodness for the sake of egoistic pride and self-will. In the Indian traditions, it is seen as "ignorance" (avidya), a failure to see that you are part of one all-encompassing Spiritual Reality and a bondage to the desires of the individual isolated ego.
For Indian idealism, liberation from egoism and the ignorance it brings is accomplished by a personal realization of the unity of all things in the universal Self. In this tradition, too, reason is not a reliable way to God because reason shares in the fundamental ignorance that is the bondage of the ego. Again, reason is very important, and argumentation and inference play a major part in Indian religious thinking. But, as David Hume said, "reason is the slave of the passions," and the fundamental orientation of reason is set by basic human desires and attitudes, operating at a sub- (or supra-) rational level. Where love of individual ego predominates, reason will only serve to make egoism more effective. But where love of the Supreme Self predominates, reason will help us to discern where true human liberation lies.
The idealist view differs from the theistic view, but they can be seen to be complementary perspectives on the relation between finite selves and the Supreme Self. In detail, they cannot both be true. But they can be seen as conceptual models drawn from different ways of interpreting experience, both fail to be wholly adequate and each stresses distinctive insights. As the basic models are elaborated by philosophers (like San-kara and Ramanuja in the Indian tradition or Maimonides, Aquinas, and Al Gazzali in the Abrahamic tradition), they generate inferences that can be checked against scientific knowledge, for example. In that way, reason helps to verify or disprove specific religious interpretations, though it rarely generates wholly conclusive or incontestable conclusions. Arguments for God can be seen as ways of showing the coherence of religious interpretations with scientific ones. That is exactly what Aquinas was doing when he wrote of the "five ways of demonstrating the existence of God." He was taking the best scientific thought of his day, based on Aristotle, and showing how the idea of God as the perfect, necessary, First Cause was a coherent and plausible corollary of Aristotelian theories of causality.
The price of this attempt was that, as Aristotelian notions of causality were dropped, Aquinas' specific arguments lost plausibility, and Kant was able to show how Newtonian physics no longer made the Aristotelian arguments seem plausible. Kant, in turn, took some of the leading basic beliefs of his own eighteenth-century Prussian culture—beliefs in human freedom, individual moral responsibility, and self-improvement—and made them into a model for conceiving God in a new way, as the reality that made free moral self-improvement obligatory and possible in a basically mechanistic universe.
It was not at all, as some mistakenly think, that Kant set out to destroy all metaphysical thinking and all belief in or rational "arguments for" God. On the contrary, he set out to place metaphysics on a firm basis for the first time. A crucial step in his philosophy was to distinguish "theoretical" from "practical" reason and to root moral and religious beliefs in the realm of practical reason. If you can follow him in making that distinction, then Kant's arguments for God consist in showing how God is not necessary for theoretical reason (i.e., for Newtonian physics) but is necessary for practical reason (for rational commitment to the absolute demands of universal morality).
This is not an argument from universally accepted morality to God, who suddenly pops out of the argument unexpectedly, like a rabbit out of a hat. It is an attempt to construct a conceptual model for Spirit (which Kant assumed to be the "noumenal" basis for the world of appearances) that would reinforce the new emphasis on human autonomy and moral freedom that was the focus of the revolutionary spirit of the eighteenth century. This model downgraded the "servile" obedience of worship but found the basis of moral autonomy in the self-legislation of practical reason, the practical will of the universe toward free self-improvement for all.
When so-called proofs of God are seen as attempts to construct a systematic conceptual scheme within which Spirit can have a coherent place, then we can better understand both their cultural and historical conditions and their real character as imaginative constructions of a worldview from a spiritual perspective.
It can also be seen that the worldview of atheistic materialism has precisely the same intellectual character, except that it is an imaginative construction that excludes Spirit from serious consideration. Sometimes—in the work of Richard Dawkins, for example—a neo-Darwinian model of adaptation through chance mutation and blind selection is taken as the key model for understanding the whole of reality. That model must then be rationally assessed in exactly the same way as theistic or idealist models will be assessed.
It can be said to be verified if it seems to be economical, fruitful, and comprehensive—if it requires few basic concepts and entities, if it motivates scientific inquiry, and if it can give a good explanation for all features of the humanly experienced world. It will be falsified if it fails to explain aesthetic, moral, or religious beliefs well, if it threatens human dignity and freedom, and if it omits many features of the experienced world.
But such verification and falsification are never conclusive. It is always a matter of finding a cumulative set of reasons that together point to a favored model and trying to show that apparent counter instances are due to misunderstandings or oversimplifications. Both theism and materialism can be rationally held and argued for, but reason is never decisive in either case. The question of the sorts of experience you have, the importance you give to them, and the sorts of concepts you find most adequate to interpret them looks as though it will remain highly contested for the foreseeable future.
That is why there are no knock-down proofs of God and why there could never be. There are no knock-down proofs of materialism or atheism either. To say that there is evidence for materialism and not for God is to beg the question and use rhetoric instead of rational argument. For the sciences, which quite intentionally deal only with the material and which, therefore, insist on the need for material evidence, have no view on whether there is a nonmaterial reality for which one would need nonmaterial evidence. It is perfectly rational to hold that there is, but reason is not the final arbiter of the issue. As Blaise Pascal said, "The heart has its reasons, of which reason is unaware." God is not known by reason, though reason has an important part to play in constructing human ideas about God. God is known by the heart, by a passionate commitment to the ultimate authenticity of a specific sort of human awareness of truth. Materialism is also known by the heart, in just the same way. But, for the theist, it is God who is believed to grasp the heart and unite it to the Divine in such a way that to deny divine reality becomes a betrayal of the deepest personal commitment there could be.