general development of both renaissance and post renaissance philosophy up till today. It would

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1 Introduction: The scientific developments of the renaissance were powerful and they stimulate new ways of thought that one can be tempted to disregard any role medieval thinking plays in the general development of both renaissance and post renaissance philosophy up till today. It would be a mistake to take it that Descartes or Locke achieved a total radical break from the past and inaugurated a completely new philosophical era. One cannot understand scholars like Descartes or Locke without having some real knowledge of medieval thinking. Thus, in this essay, I wish to show that Aquinas, a thinker of the middle ages, thought on knowledge is of permanent value and that it deserves respect and due consideration for today s discourse of philosophy. 1 Aquinas philosophy is based on the premise that knowledge and being are correlates. In so far a thing is, it is knowable and in this resides its ontological truth. Thus, the Thomistic theory of knowledge. is a realist theory. It plays an integral part in his metaphysics and philosophy of being. Aquinas is not interested in the problem of objective as we have it in modern thinking and today rather, he is much more interested in how we acquire our knowledge and put them to use. Simply put, he investigates the process of knowledge. He identified three levels of acquiring knowledge namely: sense-experience, imaginations or ideations and intellection. Aquinas thus made an important contribution to epistemology, recognising the central part played by sense perception in human cognition. It is through the senses that we first become acquainted with existent, material things. Sense experience is contact with material things through the senses which supplies materials for the formation of ideas in imagination upon which understanding climbs to contemplate. It is thus a misconception to suppose that the fundamental role of sense 1 (5 Jan 2011) 1

2 perception was a discovery of the classical British empiricist. What is Epistemology What we have set to do is to examine the central theses of Aquinas epistemology, hence it would be necessary to give an over view of what epistemology is. Epistemology is the investigation into the grounds and nature of knowledge itself. The study of epistemology focuses on our means for acquiring knowledge and how we can differentiate between truth and falsehood. Modern epistemology generally involves a debate between rationalism and empiricism, or the question of whether knowledge can be acquired a priori or a posteriori. 2 Epistemology is important because it is fundamental to how we think. Without some means of understanding how we acquire knowledge, how we rely upon our senses, and how we develop concepts in our minds, we have no coherent path for our thinking. A sound epistemology is necessary for the existence of sound thinking and reasoning, this is why so much philosophical literature can involve seemingly arcane discussions about the nature of knowledge. Unfortunately, atheists who frequently debate questions that derive from differences in how people approach knowledge aren't always familiar with this subject. 3 According to empiricism, we can only know things after we have had the relevant experience this is labeled a posteriori knowledge because posteriori means after. According to rationalism, it is possible to know things before we have had experiences this is known as a priori knowledge because priori means before. 4 Empiricism and rationalism exhaust all possibilities either knowledge can only be acquired after experience or it is possible to acquire at least some knowledge before experience. There are 2 Cf. Microsoft Encarta Premium Ibid. 4 Ibid. 2

3 no third options here (except, perhaps, for the skeptical position that no knowledge is possible at all), so everyone is either a rationalist or an empiricist when it comes to their theory of knowledge. 5 The Problem Of Knowledge Nearly every great philosopher has contributed to the epistemological literature. Some historically important issues in epistemology are: whether knowledge of any kind is possible, and if so what kind; whether some human knowledge is innate (i.e., present, in some sense, at birth) or whether instead all significant knowledge is acquired through experience (empiricism; rationalism); whether knowledge is inherently a mental state (behaviourism); whether certainty is a form of knowledge; and whether the primary task of epistemology is to know Innate idea in philosophy is the notion that an idea allegedly inborn in the human mind, as contrasted with those received or compiled from experience. The doctrine that at least certain ideas (e.g., those of God, infinity, substance) must be innate, because no satisfactory empirical origin of them could be conceived, flourished in the 17th century and found in René Descartes its most prominent exponent. 6 Aquinas Saint Thomas Aquinas was born around 1225 in the castle of Roccasecca in the Kingdom of Napels. At the age of five he was sent by his parents to the Benedictine Abbey of Monte Cassion as an oblate where he started his education. In 1244 Aquinas entered into the religious order of the Dominicans. He received and taught theology in Paris, France. Aquinas was an 5 Ibid. 6 (5 Jan. 2011) 3

4 Italian philosopher and theologian in the scholastic tradition. He is the foremost proponent of natural theology and one of the thirty-three Doctors of the Church. Aquinas was a creative writer. His most extensive work is the Summa Theologica, which he probably wrote between 1265 and 1272 but left unfinished. In January 1274, Pope Gregory X sent Aquinas to attend the Second Council of Lyons. On the way to the council he stopped at a castle and there became seriously ill. Seven weeks later, at the age of forty-nine, Aquinas died on March 7, The philosophical understanding on human nature, of the soul and body is the foundation of his epistemology. Human beings are a harmony with body and soul. The soul of a being is relying on the body as the body is relying on the soul. Without the soul, the body would have no form and without the body, the soul would not have its required organs of sense. Since the soul confers upon our bodily form, it is the soul that gives us life. The soul also accounts for our human capacity for sensation and the powers of intellect and will. Senses are naturally determined to the apprehension of particulars, not universals. Human intellect knows what it does through its interaction with real concrete objects. Our minds are capable to seize what is permanent and balanced within rational things. 8 When we sense concrete objects or people, we know their essence even though they are in the process of change. Our intellects then see the universal in particular things, we then separate the universal from the particular and in doing so we apprehend the universal. This psychological capability of separating the universal from the particular is what Aquinas calls active intellect. Aquinas rejected that universals exist apart from certain concrete objects. Universals are not taken as existing realities but are viewed as intelligibilities with a basis in what is common to existents. Man can form some intellectual concept and judgments with regard to immaterial 7 Cf. Article by Anthony J. Suh: Saint Thomas of Aquinas and Friedrich Nietzsche on:epistemology and Metaphysics Human Morality God 8 Ibid. 4

5 objects and beings by negating particular aspects of the body and by means of analogy. We can have no knowledge and understanding without sense experience. Nothing can be intellect that was not first in the senses. Sense experience provides the passive component of knowledge and the mind provides the active component of knowledge. Aquinas epistemology is centered on his comprehension human nature, but concludes with sense objects 9 Theory of Knowledge (Epistemology) To explain the process of knowledge, Thomas Aquinas has recourse neither to the innate ideas of Platonism nor to the illumination of Augustine. Instead, he postulates a cognitive faculty naturally capable of acquiring knowledge of the object, in proportion to that faculty. Agreeing with Aristotle, he admits that knowledge is obtained through two stages of operation, sensitive and intellective, which are intimately related to one another. Also, like Aristotle, Aquinas believed that knowledge (scientia) comes through demonstrative syllogisms (basically deductive arguments with true premises). The premises to these syllogisms, in turn, must be inferred from other demonstrative syllogisms. To avoid an infinite regress of syllogisms, Aquinas argued that some premises are not conclusions of other syllogisms. Rather, there are some premises (some knowledge) that form the foundation of all demonstrations. 10 The proper object of the sensitive faculty is the particular thing, the individual; the proper object of the intellect is the universal, the idea, the intelligible. But the intellect does not attain any idea unless the material for that idea is presented to it by the senses: Nihil est in intellectu quod prius non fuerit in sensu. The two cognitive faculties, sense and intellect, are naturally capable of acquiring knowledge of their proper object, since both are in potency the sense, toward the individual form; and the intellect, toward the form of 9 Ibid (5 Jan 2011) 5

6 the universal. The obtaining of the universal presupposes that the sensible knowledge of the object which lies outside us comes through the impression of the form of the object upon the sensitive faculty. This is likened to the impression of the seal upon wax. Upon this material impression the soul reacts according to its nature, that is, psychically, producing knowledge of that particular object whose form had been impressed upon the senses. Thus the faculty which was in potency is actuated with relation to that object, and knows and expresses within itself knowledge of that particular object. 11 But how is the passage made from sensitive cognition to that which is intellective? Or, rather, how is the individual form which is now offered by sensible cognition condensed into an idea and thus made the proportionate object of the intellect? To understand the solution to the problem, it is necessary to recall the theory of Aristotle which Aquinas makes his own; that is, that the individual form is universal in potentia. It is the matter which makes the form individual. Hence if the form can be liberated from the individualizing matter, or dematerialized, it assumes the character of universality. According to Thomas Aquinas, this is just what happens through the action of a special power of the intellect, i.e., the power by which the phantasm (sense image) is illuminated. Under the influence of this illumination, the form loses its materiality; that is, it becomes the essence or intelligible species (species intelligibilis). Thomas call this faculty the intellectus agens (agent intellect), and it is to be noted that for Thomas the intellectus agens is not, as the Averroists held, a separate intellect 11 (5 Jan 2011) 6

7 which is common to all men. 12 For Aquinas, the agent intellect is a special activity of the cognitive soul, and it is individual and immanent in every intellective soul. The species intelligibilis is then received by the intellect, which is called passive since it receives its proper object, and become intelligible in act. Note that according to Aquinas the form, both intelligible and individual, is not that which the mind grasps or understands (this would reduce knowledge to mere phenomenalism), but is the means through which the mind understands the object (individual form) and the essence of the object ( forma intelligibilis ). Knowledge thus has its foundation in reality, in the metaphysical. Furthermore, since the cognitive faculty is in potency, when it becomes actuated, it becomes one with the form which actuates. Thus it may be said, in a certain sense, that the intellect is identified with the determined form which it knows. For Aquinas all the data of sense knowledge and all intelligible things are essentially true. Truth consists in the equality of the intellect with its object, and such concordance is always found, both in sensitive cognition and in the idea. Error may exist in the judgment, since it can happen that a predicate may be attributed to a subject to which it does not really belong. Besides the faculty of judgment, Aquinas also admits the faculty of discursive reasoning, which consists in the derivation of the knowledge of particulars from the universal. Deductive, syllogistic demonstration must be carried out according to the logical relationships which exist between two judgments. In this process consists the science which the human intellect can construct by itself, without recourse either to innate ideas or to any particular illumination Ibid. 13 Ibid. 7

8 How then do we come to know these foundational propositions? Without getting bogged down into the details of his theory, Aquinas, who held to a form of empiricism, tells us that we can know these propositions only through sense experience. We perceive an object (say a man) and then, through our cognitive faculty known as the active intellect, abstract the essence or universal from it (in this case, rational animal). Leaving aside the question of how our minds can abstract universals from particulars, Aquinas is faced with the problem of how men can come to know God. If all knowledge is acquired through sense perception and since God is not sensible, how can we even form a conception of God through our active intellect, let alone prove his existence? The answer that Aquinas gave was unconvincing. He asserts that while we cannot know God directly, we can know him (both form the concept of God and know he exists) by analogy. Sensible objects, in that they are finite and contingent are said to reveal God s infinity and necessity. But why does it follow that because the objects of our experience are finite and contingent there must be a God behind them who is infinite and necessary? It is at this point that Aquinas resorts to his famous proofs for God s existence. These proofs run as follows. Since all objects of our senses are contingent, it is possible for all these objects not to exist. Aquinas then adds, But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. 2 He then infers that if this were true, nothing would exist now since if all things were contingent and at one time nothing existed, then contingent things would not have come into existence. Next he argues that since something does exist, there must be something that is necessary. This necessary thing must have its necessity in itself and not from anything 8

9 else, since this would entail an infinite number of necessary things. He concludes by identifying this necessary thing with God. Hence we can have knowledge of God s existence even though this knowledge of him is indirect. 14 Somethings can be said about this type of argument. Even if we grant that something necessarily exists, why does this have to be God. Could not the universe be necessary? just because each particular part could possibly not exist does not mean the whole could not exist. 3 Furthermore, just because it is possible for all contingent things not to exist does not mean that at one time they did not exist. Why is an infinite number of necessary things deriving their necessity from other things impossible? In a debate with Jesuit Frederick Copleston on the existence of God, Bertrand Russell said he could imagine an infinite chain of contingent things causing one another. Whether he could or not is beyond the point. What should be noted is that it is not, prima facie, clear that there could not be an infinite number of necessary things. Even if this argument proved the existence of a god, it does not prove the existence of the Christian God. 15 What we can conclude from this brief discussion of Aquinas is that the epistemology he adopts from Aristotle controls his apologetical argument. However, the conclusion that Aquinas wishes to reach, that the Christian God exists, does not follow from this epistemology. The irony is that the very epistemology by which Aquinas tries to explain knowledge precludes him from having knowledge of God Ibid. 16 Ibid. 9

10 Epistemology Of Aquinas When reading the epistemology of Aquinas, one will eventually be presented with the problem of whether or not the human soul in the present state of life can understand immaterial substances in themselves. This is an important concept in Aquinas epistemology because if the human soul in its present state on earth can know the immaterial, then there are important consequences to this conclusion that contradict much of what Aquinas has previously stated. Consideration will be given to the roles of the active and passive intellects and if and how angels are to be known by the intellect as they are in themselves. First, it is necessary to define some important terms Aquinas uses that will be of particular concern in this analysis. 17 It is first essential to clarify some key terms used by Aquinas in his explanation. To begin with, the term soul is defined as the first intrinsic principle of life in a living body. The human soul specifically is the first principle of all human, rational life. Next, the term matter is defined as the principle in a thing s being by which it can be determined by form. In Thomistic and Aristotelian philosophy matter is specified as not having the ability to be observed or be even of itself actual. 18 The answer given by Aquinas to this problem begins with an assertion of the philosopher Plato, that immaterial substances are not only understood by us, but are the objects we understand before all else. For the teaching of Plato was that immaterial subsisting forms, which he refers to as Ideas, are the proper objects of our intellect, and are consequently first and per se understood by us. Further he states that material objects are known by the soul inasmuch as phantasy and sense are mixed up with the mind. Hence the purer the intellect, the better it perceives the 17 (5 Jan 2011) 18 Ibid. 10

11 intelligible truth of those things immaterial. 19 Another problem to give consideration to when discussing this topic could be why our God, being immaterial Himself, would not allow our human intellect in its present state on earth to have the ability to know God s own essence fully. Why would a loving Creator deny His perfectly loved creations this capability? A possible response to this could be found in our recognizing the perfect infinitude of God. One must be aware of the infinite and unchanging fullness of perfection that is held in the essence of God, and it seems that it would be impossible for the human intellect to be able to grasp this fully in our human intellects, for we would have to have ourselves the infinite mind of God to be able to comprehend His infinite and most perfect essence. 20 Lastly, substance is identified as a being that exists actually in itself rather than in another. Therefore, an immaterial substance is a being existing actually in itself while being completely devoid of matter. In the fourth objection Aquinas turns to the Commentator s argument that nature itself would be frustrated in its very end were we unable to understand abstract substances, because it would mean that what was made to be in itself naturally intelligible not able to be understood at all. He affirms that in nature nothing is idle or purposeless, therefore it would seem that immaterial substances could be understood by the human intellect. 21 Evaluation While a Platonic and Augustinian epistemology dominated the early Middle Ages, the translation of Aristotle s On the Soul in the early 13th century had a dramatic effect. Following 19 Ibid. 20 Ibid. 21 Ibid. 11

12 Aristotle like we said before, Thomas Aquinas recognized that there are different kinds of knowledge. Sense knowledge is what results from sensing individual things: thus, one sees a tree, hears the song of an oriole, and tastes or smells a peach. Thomas considered sense knowledge to be low-grade because it has individual things as its object and is also shared with brute animals. Sensation itself does not involve the intellect and is not properly speaking knowledge (scientia). 22 It is characteristic of scientific knowledge to be universal; the more general in scope a piece of knowledge is, the better. This is not to diminish the importance of specificity. Scientific knowledge should also be rich in detail, and God s knowledge is the most detailed. The detail, however, must be essential to the thing being studied and not peculiar to just some instances of that kind. Although Thomas thought that the highest knowledge humans can possess is knowledge of God, knowledge of physical objects is more attuned to human capabilities, and only that kind of knowledge was extensively discussed here. 23 In his discussion of knowledge in Summa theologiae, Thomas Aquinas argues that human beings do not know material objects directly, nor are such things the principal object of knowledge. Knowledge aims at what is universal, while material things are individual and can be known only indirectly. Elaborating on the thought of Aristotle, Thomas claims that the process of thinking that accompanies knowledge consists of the active intellect (intellectus agens) abstracting (abstrahens) a concept from an image (phantasma) received from the senses. 24 In one of Aquinas accounts of the process, abstraction is the process of isolating the universal elements of an image of a particular object from those elements that are peculiar to the object Ibid. 24 Ibid. 12

13 For example, from the image of a dog the intellect abstracts the ideas of being alive, being capable of reproduction, movement, and whatever else might be essential to being a dog. All these ideas are common to all dogs because they are essential to them. These ideas can be contrasted with the ideas of being owned by James and weighing five pounds, namely, with properties that vary from dog to dog. 25 Aristotle typically spoke of a form as being in the intellect of the knower, whereas the matter of an object is unintelligible and remains extramental. While it was necessary for Aristotle to say something like this in order to escape the absurdity of holding that a material object is in the mind in exactly the same way it is in the physical world, there is also something unsatisfying about it. Physical things contain matter as an essential element, and, if their matter is no part of what is known, then it seems that human knowledge is lacking. In order to counter this worry, Thomas revised Aristotle s theory. He said that not the form alone but the species of an object is also in the intellect. A species is a combination of form and common matter (materia communis), where common matter is contrasted with individuated matter (materia signata vel individualis), which actually gives bulk to a material object. Common matter is something like a general idea of matter. Since every animal must have a body, it is not enough to conceive of an animal merely as something that is alive. Having flesh and bones, that is, being material, is part of the essence of being an animal. Of course this materiality, which is common to every animal, is not the same as the actual flesh and bone that constitute James, hence the distinction between common and individuated matter. This abstracted species resides in a part of the soul called the passive intellect, where it is described as being illumined by the active intellect. What this process amounts to is the isolation 25 Ibid. 13

14 of those features of the intelligible species that are universal and necessary to it. Thus, to know what a human being is is to have abstracted the ideas of being rational and being capable of sensation, movement, reproduction, and nutrition and to have excluded the ideas of living in a particular place or having a certain appearance, all of which are not essential to being human. One objection that Thomas anticipated being raised against his theory is that it gives the impression that ideas, not things, are what are known. If knowledge is something that humans have and if what humans have in their intellect is a species of a thing, then it is the species that is known and not the thing. It might seem, then, that Thomas view is a type of idealism. 26 Thomas had prepared for this kind of objection in several ways. His insistence that what the knower has in his intellect are species, which includes matter, is supposed to make what is in the intellect seem more like the object of knowledge than an immaterial Aristotelian form. Also, scientific knowledge does not aim at knowing any individual object but at what is common to all things of a certain sort. In this, Thomas views are similar to those of 20th-century science. The billiard ball that John Jones drops from his porch is of no direct concern to physics. Even though its laws apply to John Jones s ball, physics is interested in what happens to any object dropped from any height, just as what Thomas says about apples in general also applies to each individual apple. 27 As assuaging as these considerations might be, they do not blunt the main force of the objection. For this purpose Thomas Aquinas introduced the distinction between what is known and that by which it is known. To specify what is known, say, an individual dog, is to specify the object of knowledge; to specify that by which it is known, say, the phantasm or the species of a dog, is to 26 Ibid. 27 Ibid. 14

15 specify the apparatus of knowledge. The species of something is that by which the thing is known; but it is not itself the object of that knowledge, although it can become an object of knowledge by being reflected upon Ibid. 15