Although born in Alpine Italy and educated in Normandy, Anselm became a Benedictine monk, teacher, and abbot at Bec and continued his ecclesiastical career in England. Having been appointed the second Norman archbishop of Canterbury in 1093, Anselm secured the Westminster Agreement of 1107, guaranteeing the (partial) independence of the church from the civil state.
In a series of short works such as De Libertate Arbitrii (On Free Will), De Casu Diaboli (The Fall of the Devil), and Cur Deus Homo (Why God became Man), Anselm propounded a satisfaction theory of the atonement and defended a theology like Augustines’, that emphasized the methodological priority of faith over reason, since truth is to be achieved only through “faith seeking understanding”. Anselm’s combination of Christianity, neoplatonic metaphysics, and Aristotelean logic in the form of dialectical question-and-answer was an important influence in the development of later scholasticism.
As a philosopher, Anselm is most often remembered for his attempts to prove the existence of god: In De Veritate (Of Truth) he argued that all creatures owe their being and value to god as the source of all truth, to whom a life lived well is the highest praise. In the Monologion he described deity as the one good thing from which all real moral values derive, whose existence is required by the reality of those values. Most famously, in the Proslogion (Addition), Anselm proposed the famous Ontological Argument, according to which god is understood as “that than which nothing greater can be conceived”.
Such a being, he argued, must necessarily exist in reality as well as in thought, since otherwise it would in fact be possible to conceive something greater–something exactly similar except for its existence. Thus, at least for Anselmian believers guided by a prior faith, god must truly exist as the simple, unified source of all perfections, which excludes corruption, imperfection, and deception of eve. Reflecting on the text of Psalm 14 (“Fools say in their hearts, ‘There is no god. ‘”) in his Proslogion, Anselm proposed a proof of divine reality that has come to be known as the Ontological Argument.
The argument takes the Psalmist quite literally by supposing that in virtue of the content of the concept of god there is a contradiction involved in the denial of god’s existence. Anselm supposes that in order to affirm or deny anything about god, we must first form in our minds the appropriate concept, namely the concept of “that than which nothing greater can be conceived”. Having done so, we have in mind the idea of god. But of course nothing about reality usually follows from what we have in mind, since we often think about things that do not (or even cannot) actually exist.
In the case of this special concept, however, Anselm argued that what we could think of must in fact exist independently of our thinking of it. Suppose the alternative: if that than which nothing greater can be conceived existed only in my mind and not in reality, then I could easily think of something else which would in fact be greater than this (namely, the same thing existing in reality as well as in my mind), so that what I originally contemplated turns out not in fact to be that than which nothing greater can be conceived.
Since this is a contradiction, only a fool would believe it. So that than which nothing greater can be conceived (that is, god) must exist in reality as well as in the mind. Born to an aristocratic family living near Naples, Italy, Thomas Aquinas joined the Dominican order and studied philosophy and theology in Naples, Paris, and Kln, where he was exposed to Aristotelean thought by Albert the Great and William of Moerbeke.
During the rest of his life, he taught at Paris and Rome, writing millions of words on philosophical and theological issues and earning his reputation among the scholastics as “the angelic doctor. ” Aquinas developed in massive detail a synthesis of Christianity and Aristotelian philosophy that became the official doctrine of Roman Catholic theology in 1879. De Ente et Essentia (On Being and Essence) includes a basic statement of Aquinas’s philosophical positions.
His literary activity stopped abruptly as the result of a religious experience a few months before his death. Although he wrote many commentaries on the works of Aristotle and a comprehensive Summa de Veritate Catholicae Fidei contra Gentiles (Summa) Contra Gentiles) (1259-1264), Aquinas’s unfinished Summa Theologica (1265-1273) represents the most complete statement of his philosophical system. The sections of greatest interest for survey courses include his views on the nature of god, including the five ways to prove god’s existence, and his exposition of natural law.
Although matters of such importance should be accepted on the basis of divine revelation alone, Aquinas held, it is at least possible (and perhaps even desirable) in some circumstances to achieve genuine knowledge of them by means of the strict application of human reason. As embodied souls, human beings naturally rely on sensory information for their knowledge of the world. Anselm’s Ontological Argument is not acceptable, Aquinas argued, since we are in fact ignorant of the divine essence from which it is presumed to begin.
We cannot hope to demonstrate the necessary existence of a being whose true nature we cannot even conceive by direct or positive means. Instead, Aquinas held, we must begin with the sensory experiences we do understand and reason upward from them to their origin in something eternal. In this vein, Aquinas presented his own “Five Ways” to prove the existence of god. The first three of these ways are all variations of the Cosmological Argument. The first way is an argument from motion, derived fairly directly from Aristotle’s Metaphysics:
The second way has the same structure, but begins from experience of an instance of efficient cause, and the third way relies more heavily upon a distinction between uncertain and necessary being. Aquinas’s fourth way is a variety of Moral Argument. It begins with the factual claim that we do make judgments about the relative perfection of ordinary things.
But the capacity to do so, Aquinas argued, presupposes an absolute standard of perfection to which we compare everything else. This argument relies more heavily on Platonic and Augustinian notions, and has the advantage of defending the existence of god as moral exemplar rather than as abstract initiator of reality. The fifth way is the Teleological Argument: the order and arrangement of the natural world (not merely its existence) bespeaks the deliberate design of an intelligent creator.
Although it is an argument by analogy, which can at best offer only probable reason for believing the truth of its conclusion, this proof offers a concept of god that most fully corresponds to the traditional elements of medieval Christian theology. Since its experiential basis lies in our understanding of the operation of nature, this line of reasoning tends to become more compelling the more thorough our scientific knowledge is advanced.