Who is thomas aquinas saint

On mathematics, there are only glancing allusions in Thomas's writings. The concepts come to be in us as a result of our engagement with the sensible world.

So it is important to stress that logic concerns formal relations between concepts. It is not concerned with the sort of developmental and causal relations studied within the the discipline of psychology. Thomas does not advocate a kind of proto-psychological account of logic as one might see in various 19th century accounts.

This means that logic rides piggy-back on direct knowledge of the world and thus incorporates the view that what is primary in our knowledge is the things of which we first form concepts.

Mathematical entities are idealizations made by way of abstraction from our knowledge of sensible things. This epistemological primacy of knowledge of what we grasp by our senses is the basis for the primacy of the sensible in our language.

Language is expressive of knowledge, and thus what is first and most easily knowable by us will be what our language first expresses.

That is the rule. It is interesting to see its application in the development of the philosophy of nature. The first thing to notice about this is the assumption that we begin our study of the natural world not with the presumed ultimate alphabet with which macrocosmic things are spelled, but with a vague and comprehensive concept which encompasses whatever has come to be as the result of a change and undergoes change.

The reader of Aquinas becomes familiar with this assumption. Thomas learned it from the beginning of Aristotle's Physics. Now what is to us plain and clear at first is rather confused masses, the elements and principles of which become known to us later by analysis. Thus we must advance from universals to particulars; it is a whole that is more knowable to sense-perception, and a universal is a kind of whole, comprehending many things within it, like parts.

Much the same thing happens in the relation of the name to the formula. A name, e. Similarly a child begins by calling all men father and all women mother, but later on distinguishes each of them.

Physics , 1, 1. So, for example, in giving the 1st way of proving the existence of a god in the Summa Theologiae , Thomas will explicitly abide by this order when he says that we should begin with what is most manifest to us, namely, motion.

Then, specifying the subject further, one seeks properties of things known through the less common concepts. For example, in plane geometry, one would begin with plane figure and discover what belongs to it as such.

Then one would turn to, say, triangle and seek its properties, after which one would go on to scalene and isosceles. So one will, having determined what is true of things insofar as they are physical objects, go on to seek the properties of things which are physical objects of this kind or that, for example, living and non-living bodies.

Thomas emphasizes those passages in the Aristotelian natural writings which speak of the order of determination, that is, of what considerations come first and are presupposed to those that come later. In several places, Thomas takes great pains to array the Aristotelian natural writings according to this Aristotelian principle, most notably perhaps at the outset of his commentary on Sense and sensibilia.

The Physics is the first step in the study of the natural world and exhibits the rule that what is first and most easily known by us are generalities. The language used to express knowledge of such generalities will have, as we shall emphasize, a long career in subsequent inquiries, both in natural philosophy and beyond.

What is sometimes thought of as a technical vocabulary, perhaps even as Aristotelian jargon, is seen by Thomas Aquinas as exemplifying the rule that we name things as we know them and that we come to know more difficult things after the easier things and extend the language used to speak of the easier, adjusting it to an ever expanding set of referents.

Thomas points out that the characteristic features of how we know some subject should not in general be attributed to that subject as if elements of what we know of it. So, although natural things are first thought of and analyzed in the most general of terms, there are not any general physical objects, only particular ones. Thus, in seeking to discern what is true of anything that has come to be as a result of a change and is subject to change until it ceases to be, Aristotle had to begin with a particular example of change, one so obvious that we would not be distracted by any difficulties in accepting it as such.

Thomas pores over the analysis Aristotle provides of this instance of change and its product. These are three different expressions of the same change and they all exhibit the form A becomes B. But change can also be expressed as From A, B comes to be.

Could 1, 2 and 3 be restated in that second form? This grounds the distinction between the grammatical subject of the sentence expressing a change and the subject of the change. Only in 1 is the grammatical subject expressive of the subject of the change.

This makes clear that the different expressions of the change involve two things other than the subject of the change, namely, the characteristics of the subject before not-musical and after musical the change.

These elements of the change get the names that stick from another example, whittling wood. The term for wood in Greek is hyle and the term for shape, the external contours of a thing, is morphe. In English, form, a synonym of shape, is used to express the characteristic that the subject acquires as the result of the change, e.

The characterization of the subject prior to the change as not having the form is called privation. Using this language as canonical, Aristotle speaks of the subject of the change as its hyle or matter, the character it gains as its morphe or form, and its prior lack of the form as its privation.

Any change will involve these three elements: matter, form and privation. The product of a change involves two things: matter and form. Change takes place in the various categories of quality, quantity, place, and so on. In all cases the terminology of matter, form, and privation comes to be used.

So the terms applied in these different categories will be used analogously. The terms bind together similar but different kinds of change—a subject changing temperature is like a subject changing place or size. The analysis of change and the product of change begins with surface changes. Some enduring thing changes place or quality or quantity.

But enduring things like men and trees and horses and the like have also come into being and are destined some day to cease to be. Such things are called substances. It is a given that there are substances and that they come to be and pass away. The question is: Can the analysis of surface change be adjusted and applied to substantial change? What would its subject be?

The subject of substantial change is known on an analogy with the subject of incidental or surface change. That is, if substances come to be as the result of a change, and if our analysis of change can apply, there must be a subject of the change. The subject of a surface or incidental change is a substance.

The subject of a substantial change cannot be a substance; if it were, the result would be a modification of that substance, that is, an incidental change. But we are trying to understand how a substance itself comes into being as the result of a change. There must be a matter or subject but it cannot be matter in the sense of a substance. In order to signal this, we can call the matter prime matter , first matter. But it is important to recognize that this prime matter is not a substance, and does not exist apart from any particular substance.

It is always the matter of some substance that exists. When the discussion moves on from what may be said of all physical objects as such to an inquiry into living physical things, the analyses build upon those already completed. The peculiar activities of living things will be grouped under headings like nutrition, growth, sense perception, knowing, and willing.

Since a living thing sometimes manifests an instance of such activities and sometimes does not, they relate to it in the manner of the incidental forms of any physical object. But they are not incidental in the way that we might think of the shade of color of one's skin at any particular time, or the particular height or weight of an individual, since as activities the ability or power to engage in them proceeds from what the substance in question is.

Thomas at times will call the powers through which they are achieved necessary accidents, using accident in a sense different from more recent philosophy. While the abilities need not be exercised at any particular time or may be impeded from exercise by some condition, the substance nonetheless possesses them in principle as long as it exists.

The form such a subject takes on as the result of the change cannot be an incidental form like size or location or temperature. Substances do not become or cease to be substances as a result of changes in these incidental features.

As the analysis of incidental change makes clear, the substance previously existed without the form it acquires in the change and it could lose it and still be itself. In a substantial change, the substance itself simply comes to be, or ceases to be. The form in a substantial change must be that which makes the substance to be what it is.

Call it substantial form. Here we see the semantic plasticity of the term 'matter'. Initially in the analysis of change, 'matter' refers to the substance that takes on or loses some incidental categorical modification of that substance. Then the term is extended by analogy to cover whatever is the subject of a change of substance. Socrates or Bucephalus is a substance strictly speaking.

The forms and matter of Socrates and Bucephalus are not. They are substantial principles without being substances or quasi-substances in their own right. So the point to notice about this analysis is that substantial change is spoken of on an analogy with incidental change. The analysis of incidental change is presupposed and regulative. Moreover, the language used to speak of the elements of incidental change are extended to substantial change and altered in meaning so as to avoid equivocation.

The philosophical vocabulary arises out of analysis of what is most obvious to us and is then progressively extended to more and more things insofar as the later is made known by appeal to the prior. We see that matter and form apply in an analogous way to the various kinds of incidental change and then to substantial change. The analysis of form and matter provides a rule for knowing and naming that will characterize Thomas's use of Latin in philosophy and in theology as well.

Focusing specifically upon perception—seeing, feeling, hearing, and the like—how can we best analyze it? In continuity with what has gone before, the questions are put in this form: How best to analyze coming to see, coming to feel, coming to hear, and the like?

Seeing these on the analogy of change as already analyzed, we look for a subject, a privation, and a form. The sensing subject is the animal, but the proximate subjects to which they are attributed are the powers of sight, touch, hearing, and the like. An instance of seeing is describable as the power's moving from not seeing to seeing.

Since the object of seeing is color, the change from not seeing to seeing issues in the power having the form of color. Consider an ordinary physical change, a substance acquiring a color. Coming to see a color is not the same kind of physical change as a substance acquiring a color.

To be sure, while there are physical changes involved in sensation—the organs are altered in the way physical bodies are—that is not the change involved in perception as such. Consider again that in feeling a warm or cold body the hand's own temperature is altered by the contact.

But feeling cannot be just that, since any two physical bodies that come into contact undergo a similar alteration of temperature. But not all physical bodies feel the temperature. Feeling the temperature, becoming aware of it, is another sort of change, however much it involves a contemporaneous change in the organs of sense similar to ordinary physical change. Having the color or temperature in this further sense is thus made known and named by reference to physical change.

The fundamental difference between the two ways of acquiring a form is this: in a physical change of color, the change produces a new numerical instance of the color.

In grasping or sensing a color, a numerically new instance of color does not result. And yet what was potentially visible becomes actually visible. There is actuality in the world where before there was only potentiality--an actuality of the seen color, and an actuality of color not in the mode of existence that color has in physical things.

We have here the basis for talk of immateriality in perception. If the acquiring of a form by matter in physical change results in a new instance of the form and this is not the case with perception, we can make the point that acquiring the form in sensation is not identical to the acquiring of the form by matter in the primary sense. Thus, we both want to speak of the subject of sensation on an analogy with physical change and to distinguish the former from the latter.

This is done by speaking of the immaterial reception of a form. Nonetheless, the sense power is implemented in a physical organ, and thus matter for the change of form in sensation in an analogous sense. Because in sensation the sense organ is physically altered and the matter of sensation in this analogous sense, we can say that actual sensation is in some respects physical, and in another not.

It is important to pay attention again to the order of learning and naming, and what we are justified in saying at this point about the use of the words involved in describing this change. Now, in his interpretation of Aristotle's De anima Thomas defends a view that was as contested in his own time as it is almost an orphan in our own. Among the tenets of so-called Latin Averroism was the view, first held by Averroes, that the move from perceptive acts to intellection is not one from a lower to a higher set of capacities or faculties of the human soul.

Aristotle contrasts intellection with perception, and argues that the former does not employ a sense organ because it displays none of the characteristics of perception which does employ an organ. Thus insofar as sensation can be said to be in some respects material and in others immaterial, intellection is said to be completely immaterial. But on the Latin-Averroistic view, Aristotle is not thus referring to another capacity of the human soul, the intellect, but, rather, referring to a separate entity thanks to whose action human beings engage in what we call thinking.

But the cause of this, the agent intellect, is not a faculty of the soul. Aristotle had distinguished at least two intellects, a possible and an agent. The proof for incorruptibility which results from an activity that does not employ a corporeal organ is therefore a statement about the incorruptibility of this separate entity, not a basis for arguing that each human soul is incorruptible because it has the capacity to perform incorporeal activities.

The Latin-Averroists consequently denied that Aristotle taught personal immortality. Given this consequence, Thomas's adoption of the opposite interpretation—viz. Thomas is frequently said to have baptized Aristotle, which seems to mean that he fitted him to the Procrustean bed of Christian doctrine. Of course, the full Christian view is not simply that the soul survives death but that it will be reunited with body, and Thomas nowhere suggests that there is any intimation of this in Aristotle.

Oddly enough, it is often friends of Thomas who suggest that he merely used Aristotle and was not chiefly concerned with what Aristotle might actually have intended. However, this is an extraordinary approach to reading Thomas. It would be less of an accusation to say that he got a passage wrong than that he pretended it meant something he knew it did not. However, the important point is whether Thomas's reading is or is not supported by the text.

When he commented on the De anima , he seems not to be concerned with the flare up in Paris over Latin Averroism. This is the basis for dating the commentary in , before Thomas returned to Paris.

The commentary, accordingly, cannot be read as though it were prompted by the controversy. Of course, some might still say that Thomas had long term interests in taming Aristotle to behave in a Christian way.

On the contrary, as it happens, during the second Parisian period in the thick of the Latin-Averroist controversy, Thomas wrote an opusculum dedicated to the question: what did Aristotle actually teach? The work is called in the Latin, De unitate intellectus contra averroistas , On there being only one intellect contra the Averroists. This little work is absolutely essential for assessing the nature of Thomas's Aristotelianism.

He provides us with an extended textual analysis to show that the rival interpretation cannot be sustained by the text and that the only coherent reading of the De anima must view the agent and possible intellects as faculties of the human soul. His interpretation may be right or wrong, but the matter must be decided on the basis of textual interpretation, not vague remarks about Thomas's intentions.

Philosophers nowadays will want to know how this account of substance places Aquinas on the question of the relation of body and soul with respect to Dualism and Physicalism.

Not easily. Aquinas maintains that the soul is capable of existing apart from the living body after the death of the body, because the soul is incorruptible. However this picture fails to recognize the Aristotelian terms of the account that Aquinas provides of soul and body.

Thomas knows and accepts Aristotle's assertion in De anima II. The soul is indeed capable of existence apart from the body at death. This incorruptibility results from the actualities of understanding and willing that are not the actualities of any bodily organ, but of the human animal as such distinguished by the rational form.

A subsistent is something with an operation of its own, existing either on its own or in another as an integral part, but not in the way either accidental or material forms exist in another.

Existing on its own is not distinctive of substances alone. A chair is a particular thing, and thus a subsistent. But on Aquinas' account it is not a substance; it is rather an accidental unity of other subsistents which may or may not be substances. A hand has an operation distinctive of it as an integral part of a living body, an operation different from the operation of the stomach; it is a particular thing and also a subsistent.

Summa Theologiae Ia. And yet being an integral and functional part of a substance, it does not have the complete nature of a substance. A substance, on the other hand, is something that is both subsistent and complete in a nature—a nature being an intrinsic principle of movement and change in the subject. A human soul is a constitutive element of the nature of a human substance.

It is the formal principle of a human substance. It is what is specified when we say what the substance is. But it is incomplete. What it is for a soul to be is to be the form of some substance. As the principle of a nature, its nature is to be the formal element of a complete substance. Consequently, it doesn't have its own nature and is not a substance in its own right, even if it is capable of subsisting apart from the living body.

It is because it is naturally incomplete as subsisting apart from the body that Thomas sees this state as unnatural for it, and an intimation of, but not an argument for, the resurrection of the body. Question Ia. Thomas begins 75 by pointing out that his concern is the concern of a theologian, and that the theologian is concerned with human nature primarily in relation to the soul.

He is concerned with the body only in its relation to the soul. The body of the question is filled with philosophical argument, and yet its order and point is theological. That theological order and point, however, can lead to certain philosophical distortions concerning the soul if one isn't careful. So Thomas is very careful.

Considered as a substantial form of a material body, the soul exists in a living being as the substantial form of an animal. Here it is important to clarify. In the first way, any form as such is immaterial because it is not a material principle. It is distinguished as a principle of actuality in a being from the material principle which is a principle of potentiality and change in corporeal beings.

In that sense, any substantial form whatsoever will be immaterial, including the substantial form of an oak tree or the substantial form of a dog. And so also is the substantial form of the human immaterial in that sense.

Aquinas is explicit about this when he proves that the human soul is immaterial in Summa Theologiae Ia. It is immaterial in just the way in which any form whatsoever is immaterial. But in the second way, 'immaterial' is said of subsistent forms—forms that subsist without matter like angels or spiritual substances in general. In But then immediately in The souls of other animals are incorporeal in the sense of Socrates, the man, has vital activities that are the activities of a living animal, like sensation, nutrition, reproduction, and so on, activities that are not distinctive activities of the soul itself as intellect is in the human case.

Since these are activities of Socrates and not activities of the soul, Socrates and the soul are not identical. And so Socrates, if anything, is a living animal just like the other animals. Tacitly this leaves open the possibility that there might be an animal soul for Socrates that is not identical to the intellectual soul, and as shown in This possibility of two souls in Socrates, an animal soul and an intellectual soul will only be excluded later in question But in conjunction with the result of This result shows the soul to be a subsistent form that can exist without out matter.

And so it is now seen to be an immaterial subsistent in the second sense described above, not just the first sense. Now 'immaterial' characterizes its mode of existence, not just the negative fact that it is immaterial like all other forms are immaterial. So the difference between the human intellectual soul and the souls of other animals is that while both are immaterial in the first sense, the sense of not being material principles, the intellectual soul is an immaterial subsistent in the second sense while the souls of other animals are not immaterial subsistents.

A material form is a form that is not an immaterial subsistent; it exists either as an accident in a corporeal subject or as a substantial form in a corporeal subject, and does not subsist. So the substantial forms of bodies, particularly the souls of living bodies, are in general material forms with the exception of the intellectual soul.

The souls of other animals are immaterial in the first sense and material with regard to the second sense, while the human soul is both immaterial in the first sense and immaterial in the second sense. Confirmation of this distinction of senses of 'immaterial' comes when in the very last article of the question, The souls of other animals are not directly generated and do not directly corrupt. It is the living animal that corrupts. But their souls can be said to corrupt with the animal.

Quaestiones Disputatae De Anima 2 However, the human soul, because it is a subsistent immaterial form, does not corrupt with the death of the human being. So when all these results are put together the intellectual soul is an incorporeal, immaterial, incorruptible subsistent, an immaterial form in the second sense, which looks an awful lot like an angel, since angels are also incorporeal, immaterial, incorruptible subsistents, and immaterial forms in the second sense.

Angels are complete in their natures as incorporeal, immaterial, incorruptible subsistent forms—they are thus substances properly speaking.

But Thomas had insisted all along that the soul is incomplete in its nature, even as it is an incorporeal, immaterial, incorruptible subsistent form—it is not a substance properly speaking. Still, the soul can be called substance by analogy, insofar as it is the formal principle of a substance. The argument of We've already seen that Thomas, following Aristotle, thinks asking questions about the union of soul and body makes little sense for the philosopher.

But because of the potentially distorting view of the theologian, the latter in a sense is forced to do so; the theologian has to ask philosophical questions the philosopher need not ask, in order to avoid a distorted view of the soul. So in question 76 Thomas argues for the complete unity of soul with body against various alternative positions to be found among his contemporary theological interlocutors. Thus question 75, proceeding as it does from the theological perspective, gives rise to philosophical aporiae to be solved in question And just as it was the theologian's use of philosophical arguments in 75 that threatened a distorted view, it is the theologian's use of philosophical arguments in 76 that solves the aporiae , and avoids the distortion.

Apart from anything else Thomas does in the two questions, taken together they provide an exemplar of the use of philosophy within theology, not just to advance certain theological positions but to assist the theologian in avoiding error given the exclusivity of his theological perspective.

Thomas fulfills what he himself had said is one of the roles of philosophy within theology in the first question of the Summa. There are at least three important results of Ia.

In the first place, in It might be tempting to think of the human substantial form as a kind of layering of quasi substantial forms or as composed out of them.

One substantial form for the corporeality of the body, perhaps one to account for the vegetative activities of the human being, yet another for the animal activities, and then a final one for the intellectual activities of the human being.

Recall that However, Thomas decisively rejects this plurality on the basis of the manifest unity of the human being in his acts. If there were multiple substantial forms there would be no unity to being human—multiple substantial forms implies multiple substances and multiple beings.

And yet the human being is one, a single substantial unity manifested in his or her acts. Here Thomas is relying upon the substantial unity that is obvious to the philosopher to reject a kind of substance plurality, not just soul-body dualism. In particular he relies upon the fact that it is Socrates himself who engages in intellectual activity. Again, in However, what he did not claim in In fact, now in 76 he claims it is Socrates' activity. Socrates has vital activities that do not belong to the soul alone, and yet the activity that belongs to the soul alone, understanding, is one of Socrates' activities.

But the soul is the principle of activity in living things. Thus the animal soul and for similar reasons the vegetative soul is identical in Socrates with the rational soul.

There is no plurality of substantial forms because of the unity of Socrates' activities, including both animal activities and reason. Neither is the human soul composed of any quasi-substantial forms. This is the second striking result of Socrates and his soul, while not being identical, are subjects of the same activity—not subjects of the same type of activity, but subjects of the same token instance of an activity. In 75, the soul as a subsistent with its own operation of understanding was said to be the subject of existence esse per se.

In the case of other animals it is the animal itself, the living substance, that is the subject of the act of existence, and both soul and body have existence through the substance. Here in the human case, the soul is said to be the subject of the act of existence because it has its own operation. Of course, Socrates is a substance with operations that pertain to him, animal activities, but also the operation of intellect; it is Socrates who thinks in virtue of his intellect.

So he too is the subject of the act of existence. And yet the operation in virtue of which the soul is the subject of the act of existence, intellectual activity, is the operation in virtue of which Socrates is the subject of the act of existence, again, not the same type of operation but the same token of operation. So Socrates and his soul have the same act of existence. The principle for drawing this latter conclusion is that the operation of a subject follows from the act of existing of that subject, as the actuality of a power follows from the actuality of the being.

Quaestiones Disputatae De Anima 2. So Socrates, as a living animal substance, is not identical to his soul. Anima mea non est ego Thomas asserts in his Commentary on St. Paul's First Letter to the Corinthians. It is because Socrates' soul's act of existence is Socrates' act of existence that the soul's intellectual operation is Socrates' intellectual operation.

It is also because of this sharing in the act of existence, that the soul can be the substantial form of the living human animal. Because the soul is a substantial form, it is not complete in its nature, and cannot be a spiritual substance like an angel, properly speaking. Thus the soul receives its act of existence as the soul of a human being, and cannot pre-exist the human being whose soul it is.

And yet, as Thomas argued in The third significant result is that the soul is not composed from its powers as if a unified collection of them. However, this way of speaking is for the purposes of classifying the powers. It does not signal actual ontological parts of the soul.

As the first act of a body, the soul is, like all act, ontologically simple, undivided, and un-composed. And Thomas tells us they are formally related to the soul as their principle in what Aristotle calls in the Posterior Analytics the second mode of per se predication—that mode in which the subject of a predication enters into the definition of the predicate, were one to define the predicate. From this it follows that if the human soul is incorruptible, the powers of Socrates that are powers of corporeal organs cease to exist with the death of Socrates.

And yet the power of intellect as a power of the soul without a corporeal organ remains incorruptible with the human soul. However, Thomas is clear in denying that only the intellect survives the death of the human; one cannot have a free floating incorruptible power in existence without the subject of the power in existence. All of this emphasis upon the unity of the human being comes out clearly in Aquinas' understanding of the mode of human activity as acting knowingly and willingly.

Such acting knowingly and willingly is expressed as the rational activity of an animal, that is, as animal activity distinguished formally as rational. Rationality is the distinctive form that intelligence takes in human beings as animals. Rationality involves the back and forth of argument moving from one thing known to another, and advancing in knowledge by such movement. Thus, for Thomas, while angels and God can be said to be intelligent, they are not rational.

This movement in understanding is necessary for human beings because as animals they only ever have a partial grasp of the natures of things, insofar as their knowledge depends upon always incomplete and partial sensible experience of the world. But it is sense experience, as well as the self movement that springs from it, that places human beings within the genus animal.

So human understanding and willing is intrinsically bound up with the sensate activity of an animal; as a result, rational is the form that it takes in that animal. Reason does not cause eating as something separate from it, and as an efficient cause; on the contrary, human eating is not adequately described formally unless it is described as rational eating. To fail to eat rationally is not a failure in its cause, but in the eating itself. And the human animal is not adequately described except as a rational animal, rational providing not another substance or expression of a fissure between soul or mind and body, but the fully adequate description of the human substance.

Reason does not distinguish us from animals; it distinguishes us as animals. So according to Aquinas, while it is true that the activities of intellect and will are not the actualities of any physical organs, they are nonetheless the activities of the living human animal.

The unity, harmony, and continuity of faith and reason, of revealed and natural human knowledge, pervades his writings. One might expect Thomas, as a man of the gospel, to be an ardent defender of revealed truth. But he was broad enough, deep enough, to see the whole natural order as coming from God the Creator, and to see reason as a divine gift to be highly cherished.

The Summa Theologiae , his last and, unfortunately, uncompleted work, deals with the whole of Catholic theology. He stopped work on it after celebrating Mass on December 6, All that I have written seems to me like so much straw compared to what I have seen and what has been revealed to me. Thomas held fast to the ideas he had learned at university, however, and went back to the Dominican order following his release in He was ordained in Cologne, Germany, in , and went on to teach theology at the University of Paris.

Consistent with the holy hermit's prediction, Thomas proved an exemplary scholar, though, ironically, his modesty sometimes led his classmates to misperceive him as dim-witted. After reading Thomas's thesis and thinking it brilliant, his professor, Saint Albert the Great, proclaimed in Thomas's defense, "We call this young man a dumb ox, but his bellowing in doctrine will one day resound throughout the world!

After completing his education, Saint Thomas Aquinas devoted himself to a life of traveling, writing, teaching, public speaking and preaching. Religious institutions and universities alike yearned to benefit from the wisdom of "The Christian Apostle. At the forefront of medieval thought was a struggle to reconcile the relationship between theology faith and philosophy reason.

People were at odds as to how to unite the knowledge they obtained through revelation with the information they observed naturally using their mind and their senses. Based on Averroes' "theory of the double truth," the two types of knowledge were in direct opposition to each other. Saint Thomas Aquinas's revolutionary views rejected Averroes' theory, asserting that "both kinds of knowledge ultimately come from God" and were therefore compatible.

Not only were they compatible, according to Thomas's ideology, but they could also work in collaboration: He believed that revelation could guide reason and prevent it from making mistakes, while reason could clarify and demystify faith. Saint Thomas Aquinas's work goes on to discuss faith and reason's roles in both perceiving and proving the existence of God. Saint Thomas Aquinas believed that the existence of God could be proven in five ways, mainly by: 1 observing movement in the world as proof of God, the "Immovable Mover"; 2 observing cause and effect and identifying God as the cause of everything; 3 concluding that the impermanent nature of beings proves the existence of a necessary being, God, who originates only from within himself; 4 noticing varying levels of human perfection and determining that a supreme, perfect being must therefore exist; and 5 knowing that natural beings could not have intelligence without it being granted to them it by God.

Subsequent to defending people's ability to naturally perceive proof of God, Thomas also tackled the challenge of protecting God's image as an all-powerful being. Saint Thomas Aquinas also uniquely addressed appropriate social behavior toward God.

In so doing, he gave his ideas a contemporary—some would say timeless—everyday context. Thomas believed that the laws of the state were, in fact, a natural product of human nature, and were crucial to social welfare. By abiding by the social laws of the state, people could earn eternal salvation of their souls in the afterlife, he purported. Saint Thomas Aquinas identified three types of laws: natural, positive and eternal.

According to his treatise, natural law prompts man to act in accordance with achieving his goals and governs man's sense of right and wrong; positive law is the law of the state, or government, and should always be a manifestation of natural law; and eternal law, in the case of rational beings, depends on reason and is put into action through free will, which also works toward the accomplishment of man's spiritual goals.

Combining traditional principles of theology with modern philosophic thought, Saint Thomas Aquinas's treatises touched upon the questions and struggles of medieval intellectuals, church authorities and everyday people alike.

Perhaps this is precisely what marked them as unrivaled in their philosophical influence at the time, and explains why they would continue to serve as a building block for contemporary thought—garnering responses from theologians, philosophers, critics and believers—thereafter.