HISTORY OF PHILOSOPHY - SUMMARIES
 
 
(versión en español)

 
  PLATO THOMAS AQUINAS        
 
 
 
 


SAINT THOMAS AQUINAS
(c.1225-1274)

Summary of his thought
 

 

 


INTRODUCTION

I. THE PROBLEM OF THE RELATION BETWEEN FAITH AND REASON

II. THE EXISTENCE OF GOD
     
I.1. The problem of the demonstration
     
I.2. The five ways

III. GOD ESSENCE

IV. THE CONCEPTION OF MAN

      
IV.1. The structure of created reality
      
IV.2. The man, image of God
      
IV.3. The man towards God
                 
a) God as ultimate object of knowledge
                 
b) God as ultimate object of will
                 
c) Social behaviour towards God. The law



INTRODUCTION

       Christian’s conception of the world is the result of a mixture of elements: the sacred texts and its different interpretations, sometimes even opposed, the influence of Neo-Platonism and stoicism and the controversial dialogue with classic philosophy. First of all Christianity is a salvation doctrine, that is to say, a set of ideas about reality and a set of rules whose fulfilment grant paradise to believers after this world. Nevertheless, philosophy and religion have some elements in common: philosophy tries to give a rational solution to the great problems of man, whereas religion, on the other hand, displays its own privileged solution to these problems based on faith. Naturally, religions -Christianity in this case- are not philosophy, but some of the most important elements they use in their salvation proposal have been traditional objects of philosophy, and that’s why they usually use this discipline as foundation for some of their beliefs.
       One of the most important concerns of medieval thought is the relation between theology and philosophy or, in other words, between faith and reason. The genuine problem here is to determine the relation between supernatural knowledge, achieved by revelation, and natural knowledge, achieved by the intellect and the senses. Thus, reason and faith are two different sources for knowledge that can be compatible or not.


I. THE PROBLEM OF THE RELATION BETWEEN FAITH AND REASON

       This problem reaches its culminating point with Saint Thomas and, for many theologians, its solution. The distinction between philosophy/theology rests on the difference between natural and supernatural order. They are two different levels, but they are not opposed or contradictory one to the other but complementary: the order of natural knowledge comes from human reason, from which arises philosophy with its own laws, methods and demonstrative value. The supernatural order, on the other hand, comes from revelation and faith and is essentially a dark knowledge ("the act of believing is an understanding act that asserts divine truth by the empire of the will moved by God through grace"); some of the divine truths are within the reach of the reason, others exceed our intellect. Both kinds of knowledge ultimately come from God, and for that reason they cannot be contradictory. Saint Thomas uses this explanation to reject Averroes’s theory of the double truth.
        These two spheres of knowledge can collaborate: revelation serves as guide for reason (preserving it from mistakes and indicating the final solution it must come to); and reason serves to clarify, explain and defend the mysteries of faith. The result of this collaboration is theology. Some beliefs could never be demonstrated by reason (for example, the mystery of Trinity or the Eucharist) but others can, like the basic beliefs of faith (the existence of God and the immortality of the soul). This means there are issues on which theology and philosophy cover each other (the existence of God, for example) but, in spite of it, Saint Thomas believes faith is necessary because not every man can reach the truth by means of the reason, either by lack of time or by lack of capacity; in addition, faith must guide reason to avoid mistake. Thus is necessary to distinguish two types of theologies: the rational or natural theology; which reaches God from a purely rational perspective and is called natural because is based on human capacities and the Christian or supernatural theology: which is based on faith and on the revealed doctrine but uses reason for clarifying and as dialectic weapon.


II. THE EXISTENCE OF GOD

II.1. The problem of the demonstration. Although God cannot be perceived by the senses we could think He can be directly perceived by reason. Examples of this direct knowledge are the propositions "men are rational animals" or "triangles have three sides". Saint Thomas calls this type of propositions self-evident propositions; and they are because the characteristic named in the predicate belongs essentially to the object at issue (the predicate is included in the subject). The previous examples are, in addition, evident for us because we see them as true just understanding the concept which serves as subject. If the existence of God were an essential characteristic of Him or, in other words, if His existence were included in His essence, then the proposition "God exists" would be shown as true with the mere understanding of the term "God”; some philosophers (Saint Anselm and Descartes) think so, and this reasoning is called the "ontological argument". Saint Thomas, on the contrary, declares this kind of reasoning does not fit with the example of God because God’s essence is not as clearly given to us as, for example, the essence of the triangle. This means the proposition "God exists" is not evident for us, although it is a self-evident proposition (because it is true that the existence is included in the essence of God).

II.2. The five ways. Nevertheless, Saint Thomas thinks the existence of God can be proved. He thinks the mere rational argumentation is not fit for it because we should start off from the most known for us; that is, the sensible experience. Saint Thomas’s proofs (the five ways) are a posteriori demonstrations: the existence of God is deduced as ultimate cause of the effects shown in the world. These ways do not allow an exhaustive knowledge of the essence of God -given our limited capacities- but are proof enough of His existence. Similar arguments were displayed by other philosophers, specially Aristotle and Plato, who used a similar reasoning scheme: the starting point is a real data of experience, a feature of the physical world; secondly they introduce a Metaphysical principle (this feature must have a cause which cannot be itself or this perfect feature cannot have its origin in something less perfect than itself...); on the third step they agree a concatenated causal series cannot last indefinitely, it has to have an end; and finally they conclude there must exist a supreme being.
      The first way begins observing the movement all over the world and ends up asserting the existence of God as Immovable Motor; the second way observes the existence of causes in the world and concludes the existence of an ultimate Cause; the fourth way observes the existence of different levels of perfection in the beings of the world and ends up proposing the existence of a supremely perfect being. Nevertheless, the most interesting ways are the third and the fifth. The Third Way emphasizes one of the most important features of all finite objects, the radical insufficiency of their being, their contingency: the beings of the world exist but they could equally not exist, they have specific features which they could equally not have. If they do exist but could not then we can think of a time in which they didn’t; and if they were the only beings of the world, then nothing would have existed. As this is obviously not the case, then we should conclude that along with those contingent beings there must exist a necessary being, a being which has its origin in itself instead of in another being, and that being is God. The fifth Way starts off from the existence of order in the natural world and from the necessary existence of an intelligence that guides the behaviour of those beings which do have a final purpose in the world. Natural beings do not have intelligence, so they must have been created by other being who has given them their natural disposition to those behaviours better adapted to their aims. In conclusion, there must be an Ordering Intelligence which we could call God.


III. GOD ESSENCE
     One of the main challenges Saint Thomas faces is to defend the possibility of the knowledge of God without underestimating the quality of His being. We need hold a balanced position, avoiding ends: asserting the possibility of the knowledge of God at the cost of approximating Him too much to this world (which would be an anthropomorphism); or letting our concern for His essence be so strong we solely accept a negative or an irrational approach to Him (a mystic approach, for example). Saint Thomas displays several ways to preserve this equilibrium: the affirmative way: we assign God solely those features which bring him no imperfection; the negative way: we get a negative concept of God denying the features which imply imperfection: God is immovable, is pure act, is immutable and simple; the eminence way: we assign Him those perfect features we find in other beings, but declare He have them infinitely: kindness, intelligence, will. Besides, the analogy means words do not have exactly the same meaning when we talk about God or about finite beings. They neither have a univocal nor an ambiguous meaning, but an analogical meaning, which means they have partly the same and partly different meaning.
       The five ways provide us five predicates for God: Immovable motor, uncaused Cause, necessary and supremely perfect being, supreme Intelligence. The formal constituent is the fundamental attribute that, according our knowledge, is first ontologically speaking and of which every other attribute is derived. The formal constituent of God is His subsistent being: essence and existence are identified in Him. This perfect feature is the origin of all others in him and it distinguishes his essence from the essences of created beings as essence and existence are different in the rest of beings. The divine attributes come out from the formal constituent and can be ontological or operative. The ontological attributes are features of His Being: some of them can be directly derived from the constituent attribute (simplicity, perfection, infinity, immutability and unity) and others are only indirectly derived (kindness, immensity, omnipresence and eternity); they all make God a transcendent being, completely different from all the created beings and superior. The operative attributes refer to His Acting and there are two types: immanent actions (internal): to understand and to want, and transitive actions (external): to be able. As understanding and wanting are vital actions, God’s life is also an operative attribute. On the other hand, God is free and has a will. The effects of divine will are love and joy, and its virtues are justice, mercy and liberality. The active power of God is displayed in three fundamental ways: the creation, the conservation and the government (providence).


IV. THE CONCEPTION OF MAN

IV.1. The structure of created reality

      Aquinas starts off from the contingency of all finite being. Things have not given themselves their own being: neither their existence nor their essence, and this is indeed the Metaphysical foundation for asserting the existence of God: the radical contingency of all finite being demands the existence of a being which could be a foundation for itself and for the rest of reality, that is, God. All creatures are Metaphysically made of essence and existence (they are contingent, limited); on the contrary, the only necessary and infinite being, God, is the reason of their existence. And He is the reason of the whole world in an absolute sense (God creates the world starting off from nothing) and not, as in Greek explanations, starting off from some pre-existing reality (as the Demiurge of Plato). Saint Thomas offers us a vision of creation as a hierarchically and pyramidal reality. Created beings are composed, structured. Aquinas uses Aristotelian concepts to talk about them: act and power, substance and accidents, material and form, adding the original distinction essence/existence (Metaphysical composition responsible for their contingency). The hierarchical structure of beings of the world is ordered depending on their level of simplicity and proximity to the pure existence of God. Angels (compounds of essence and existence) are on the peak of creation, and then come men (whose substantial form is the soul, which is united with material). Material world substances are a compound of material and form. The man is the intersection point between the merely corporeal and spiritual being. The "form" called soul can exist independently of the body; however, the sensitive beings -as animals- or purely vegetative -as plants- have a corruptible form that cannot exist independently of the material. The form of the inert beings and the form of the first elements are the most imperfect ones. Still on an inferior degree there are the accidental forms, which do not exist by themselves -as substances- but in another being. And finally, in the lowest degree, is the absolute potentiality of the raw material, which is pure capacity of being.


IV.2. The man, image of God

      Much more than the rest of the natural beings, but less than angels, the man reflects in his being certain proportion with the divine being, locating between two worlds: made up of material body and spiritual soul, the first one ties him to the sensible world and the second to the spiritual world. He is the most perfect being of the sensible world and the less perfect in the level of the intellectual substances. Aquinas’s conception of man resembles the Aristotelian point of view, but acquires an specific character in combination with the Christian thought: living beings have a realm of characteristic functions different from the nonliving beings: to be born, to nourish themselves, to grow, to reproduce, to move locally and to die, and in superior degrees to feel, to think and to want. Saint Thomas defines the soul as a principle of life and as the form of a physical body which potentially has life. The soul is what distinguishes the living beings from the nonliving beings.
      Saint Thomas mentions the faculties: they are the active powers of the soul and the principles of vital functions. We should distinguish between corporeal and incorporeal powers or faculties: the first ones require a corporeal organ, whereas the second ones -as understanding and will- don’t; they do operate from the essence of the soul where they belong. Apart from the intellect, divided in theoretical (which function is the knowledge of truth) and practical (which function is the action), human soul holds other three kinds of mental faculties: will or rational appetite, sensation faculties (vision, hearing, etc.) and sensuality or sensible appetite. Although Saint Thomas defends an anthropological dualism, his position is not as radical as Plato’s as he declares "man" is a conjunction of body and soul, and not solely soul (Plato). He even argues that, as the body has been created by God, we must love it as the consequence of our love for God.
 

IV.3. The man towards God

      Man belongs to natural and supernatural orders, but there is continuity between both. Thanks to the divine grace, he reaches a perfection he couldn’t have reached by himself though, on the other hand, all the spheres of the human activity should be understood within their reference towards God; this tension towards the transcendent order is particularly clear in three spheres of the human being: knowledge, moral behaviour and social behaviour.

a) God as ultimate object of knowledge: human being’s intellectual vocation towards God is clear not only in the fact that theology is the supreme science and constitutes the utmost perfection of our intelligence but, basically, in the fact that knowledge tends to truth and God is the supreme truth. Every human knowledge is ultimately knowledge of God and every truth is somehow connected with God: in the first place because God is its creator and is the one who brings intelligibility to reality (without which there would be no truth) and finally because we know God in everything else we know as the world is the "physical revelation" of God. Anyway, the supreme purpose of man is the vision of God in the other life, that is to say, a purely intellectual and direct knowledge of Him.

b) God as ultimate object of will: being and rightness are equivalent; thus God, being the superior being, is also perfect and infinite rightness. Moral life is ultimately guided towards beatitude. Saint Thomas defends a teleological point of view: the whole creation and every event of the universe have an aim. The exceptional status of man comes from the fact that, apart from God and the angels, he is the only being capable of being aware of his aims and means. Man is the only being impelled to action by ideas of good and right. The will naturally tends to good, will is that tendency to good. But this search for the good would be a total chaos without the guide of the reason, which tells us what’s good and what’s wrong. Regarding God, the supreme Good, human’s will is ruled by necessity laws: God necessarily moves our will. Regarding less perfect goods, nevertheless, the will is free. That’s the reason why ethic’s main interests are those less perfect and earthy goods whose accomplishment allow man reaching God. In his theory of the virtues, Aquinas follows Aristotle adding some elements of the Christian perspective. The virtues are those habits which allow the soul the better accomplishment of each aim. As the soul have different parts, there will also be different kinds of virtues: intellectual virtues or intellectual perfections (art, prudence, intelligence, science and wisdom); moral virtues or appetizing faculties perfections (emphasizing justice or will’s perfection) and inferior appetizing perfections (strength and temperance) which will always consist on achieving a medium point between two vices, one by defect and the other by excess. To these traditional Greek virtues Aquinas adds the supernatural or theological virtues (faith, hope and charity) which specific purpose is God and which are instilled on us by God, improving human’s natural disposition to supernatural order.

c) Social behaviour towards God. The law: once again, Saint Thomas’s political doctrine is a synthesis of Aristotelian policy and Christian beliefs. Man has a supernatural aim he must try to achieve by his social actions and life in the State, although he would only achieve them completely in the other life. The State is a natural institution based on man’s nature. Man is a political being who lives in community, which means there must be a government who care for social welfare. Being indispensable for human being, society and government are ultimately justified in God, who created human nature. As the supernatural aim of man is eternal beatitude, aim for which the Church is responsible, thus the State, though independent, must come to indirectly depend on the Church. Thus, the State must guide and legislate so that citizens live virtuously and reach that aim: eternal salvation. The law (which rests on reason and induces citizens to act) must be guided towards the attainment of social welfare.
        Saint Thomas distinguishes three kinds of laws: natural, positive and eternal law. The natural law guides and orders natural being’s actions towards their respective aims. Aquinas uses the Greek notion of nature as intrinsic dynamic principle which determines natural being’s behaviour, and thus uses also the Greek idea that “naturalness” is the perfect criterion for deciding right from wrong: natural is identified with right while unnatural is identified with wrong. Regarding this point, the main difference between Saint Thomas and Greek explanation is natural inclinations ultimately rest on God for Aquinas, God whose providence governs everything and gives them their specific disposition in order to achieve their own perfection. The eternal law involved in the nature of irrational beings passively and necessarily determines their behaviour whereas on rational beings (man) this eternal law rests on reason and is accomplished by a free will. Strictly talking, natural law for Aquinas means moral law, moral law he identifies with the human reason which distinguishes right from wrong and orders consequently. The moral law is natural and rational: rational because is dictated by reason; natural because not only reason is natural, but it identifies the best behaviour according our nature. The natural law involves the fundamental rules that govern moral life, the first of which is "do the right and avoid wrong", principle on which every other are based. Since the natural law is based on human nature, and human nature is a creation of God, the natural law is not conventional, but immutable and universal.
      The positive law is the law established by the States, but it must be the expression of the natural law, and therefore must not be conventional. Thus, those positive laws opposed to natural laws are bad laws, and it is right if the citizens refuse to fulfil them, whereas those according the natural law are good and the citizens are forced to fulfil them. Legality does not always agree with morality: if the politician promulgates a law opposed to natural law and, therefore, opposed to the divine law, it is morally right to rebel, though it is not legitimate. The natural law has its origin in a universal order: the order of the Universe, which is expression of the eternal law that rests on the reason of God and from which derives the rest of laws. The eternal law is eternal and immutable because its origin is God. God orders all actions, human and not human, towards their aims. Unlike Aristotle, for Saint Thomas rightness is founded on something more transcendental than our nature: God.

 

 

© Javier Echegoyen Olleta - translated by Isabel Blanco González