|Reading for Philosophical Inquiry: A Brief Introduction to Philosophical Thinking ver. 0.21; An Open Source Reader|
Cathedral at Marseilles, France, Library of Congress
The nature and existence of God is of vital concern to many persons as their answer to the question of how we can live meaningfully. What insights, if any, can philosophy secure about the existence of God and the presence of evil in the universe? If no knowledge or proof can be had about these essential foundations of belief and action, then how useful can philosophy be in determining matters of ultimate concern? Toward these ends, we study a number of philosophers throughout the history of Western civilization. As it turns out, however, these classical inquiries are mainly influential not so much in the philosophy of religion as in establishing useful methods of reasoning and in articulating the limits of established forms of proof.
St. Anselm forcefully argues that if the nature of God is conceptually understood, then God must be known to exist—he believes the object of an idea of ultimate perfection could not be possible unless it existed. So, in a basic sense for Anselm, "perfection" implies "existence."
Thomas Aquinas, building on ideas derived from Aristotelian science, attempts to show that many of the fundamental concepts by which we understand the nature of the universe only make sense under the assumption of the existence of God. Thomas offers five ingenious arguments; his last argument, that the intricate complexity of the physical world seems to imply God as the source of the functional unity of the universe, is, many centuries later, forcefully re-argued by analogy by William Paley.
Nevertheless, all of these ingenious proofs, according to Blaise Pascal, are "feeble reasonings." Pascal observes that the most important things in life are lived through passion and commitment, not through theoretical insight or proof. Indeed, the insightful and clever proofs for God's existence are subject to additional stunning obstacles noted by more cautious thinkers such as Gaunilo, Immanuel Kant, David Hume, and Fyodor Dostoevsky.
In the end, any positive results for the proofs for God's existence are left unanswered. Even so, important concepts, distinctions, and methods of analysis are discovered and found useful in other areas of philosophy.