Although born in Alpine Italy and educated in Normandy, Anselm became aBenedictine monk, teacher, and abbot at Bec and continued his ecclesiasticalcareer in England. Having been appointed the second Norman archbishop ofCanterbury in 1093, Anselm secured the Westminster Agreement of 1107,guaranteeing the (partial) independence of the church from the civil state. In aseries of short works such as De Libertate Arbitrii (On Free Will), De CasuDiaboli (The Fall of the Devil), and Cur Deus Homo (Why God became Man), Anselmpropounded a satisfaction theory of the atonement and defended a theology likeAugustines’, that emphasized the methodological priority of faith over reason,since truth is to be achieved only through “faith seekingunderstanding”.
Anselm’s combination of Christianity, neoplatonicmetaphysics, and Aristotelean logic in the form of dialecticalquestion-and-answer was an important influence in the development of laterscholasticism. As a philosopher, Anselm is most often remembered for hisattempts to prove the existence of god: In De Veritate (Of Truth) he argued thatall creatures owe their being and value to god as the source of all truth, towhom a life lived well is the highest praise. In the Monologion he describeddeity as the one good thing from which all real moral values derive, whoseexistence is required by the reality of those values. Most famously, in theProslogion (Addition), Anselm proposed the famous Ontological Argument,according to which god is understood as “that than which nothing greatercan be conceived”. Such a being, he argued, must necessarily exist inreality as well as in thought, since otherwise it would in fact be possible toconceive something greater–something exactly similar except for its existence. Thus, at least for Anselmian believers guided by a prior faith, god must trulyexist as the simple, unified source of all perfections, which excludescorruption, imperfection, and deception of eve.
Reflecting on the text of Psalm14 (“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 theOntological Argument. The argument takes the Psalmist quite literally bysupposing that in virtue of the content of the concept of god there is acontradiction involved in the denial of god’s existence. Anselm supposes that inorder to affirm or deny anything about god, we must first form in our minds theappropriate concept, namely the concept of “that than which nothing greatercan be conceived”. Having done so, we have in mind the idea of god. But ofcourse nothing about reality usually follows from what we have in mind, since weoften think about things that do not (or even cannot) actually exist.
In thecase of this special concept, however, Anselm argued that what we could think ofmust 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 andnot in reality, then I could easily think of something else which would in factbe greater than this (namely, the same thing existing in reality as well as inmy mind), so that what I originally contemplated turns out not in fact to bethat 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 beconceived (that is, god) must exist in reality as well as in the mind. Born toan aristocratic family living near Naples, Italy, Thomas Aquinas joined theDominican order and studied philosophy and theology in Naples, Paris, and K?ln,where he was exposed to Aristotelean thought by Albert the Great and William ofMoerbeke.
During the rest of his life, he taught at Paris and Rome, writingmillions of words on philosophical and theological issues and earning hisreputation among the scholastics as “the angelic doctor. ” Aquinasdeveloped in massive detail a synthesis of Christianity and Aristotelianphilosophy that became the official doctrine of Roman Catholic theology in 1879. De Ente et Essentia (On Being and Essence) includes a basic statement ofAquinas’s philosophical positions. His literary activity stopped abruptly as theresult of a religious experience a few months before his death. Although hewrote many commentaries on the works of Aristotle and a comprehensive Summa deVeritate Catholicae Fidei contra Gentiles (Summa) Contra Gentiles) (1259-1264),Aquinas’s unfinished Summa Theologica (1265-1273) represents the most completestatement of his philosophical system. The sections of greatest interest forsurvey courses include his views on the nature of god, including the five waysto prove god’s existence, and his exposition of natural law.
Although matters ofsuch importance should be accepted on the basis of divine revelation alone,Aquinas held, it is at least possible (and perhaps even desirable) in somecircumstances to achieve genuine knowledge of them by means of the strictapplication of human reason. As embodied souls, human beings naturally rely onsensory information for their knowledge of the world. Anselm’s OntologicalArgument is not acceptable, Aquinas argued, since we are in fact ignorant of thedivine essence from which it is presumed to begin. We cannot hope to demonstratethe necessary existence of a being whose true nature we cannot even conceive bydirect or positive means. Instead, Aquinas held, we must begin with the sensoryexperiences we do understand and reason upward from them to their origin insomething eternal.
In this vein, Aquinas presented his own “Five Ways”to prove the existence of god. The first three of these ways are all variationsof the Cosmological Argument. The first way is an argument from motion, derivedfairly directly from Aristotle’s Metaphysics: 1. There is something moving.
2. Everything that moves is put into motion by something else. 3. But this seriesof antecedent movers cannot reach back infinitely.
4. Therefore, there must be afirst mover (which is god). The second way has the same structure, but beginsfrom experience of an instance of efficient cause, and the third way relies moreheavily upon a distinction between uncertain and necessary being. Aquinas’sfourth way is a variety of Moral Argument. It begins with the factual claim thatwe do make judgments about the relative perfection of ordinary things.
But thecapacity to do so, Aquinas argued, presupposes an absolute standard ofperfection to which we compare everything else. This argument relies moreheavily on Platonic and Augustinian notions, and has the advantage of defendingthe existence of god as moral exemplar rather than as abstract initiator ofreality. The fifth way is the Teleological Argument: the order and arrangementof the natural world (not merely its existence) bespeaks the deliberate designof an intelligent creator. Although it is an argument by analogy, which can atbest offer only probable reason for believing the truth of its conclusion, thisproof offers a concept of god that most fully corresponds to the traditionalelements of medieval Christian theology. Since its experiential basis lies inour understanding of the operation of nature, this line of reasoning tends tobecome more compelling the more thorough our scientific knowledge is advanced.