I last read from Aquinas’ Summa Theologica in May of 2014. As I stated in my previous post, I enjoy reading the works of Aquinas. His writing style is concise and logical. He begins by asking a question, then he proposes several possible answers, and finally he forms his own conclusion and provides counterarguments to each of the other answers that he considered. Other philosophical writers, such as Kant, present their arguments in a convoluted fashion, which frustrates the reader rather than elucidates the concepts that the writer wishes to convey. Aquinas’s writing style does not suffer any of these defects. It allows the reader to easily comprehend the arguments and form conclusions of his own.
Question 16 examines Truth. Aquinas argues that Truth primarily resides in the intellect, and secondarily resides in physical objects. He explains that truth is found in the intellect insofar as it apprehends the essence of a thing, and that truth resides in physical objects insofar as its essence conforms to the idea within the intellect. To clarify his meaning, he makes an insightful observation about the natures of Truth and Good. Good is an attribute of a physical object, and the end of the appetite. One desires a physical object because it is Good in some sense. On the other hand, Truth primarily resides in the intellect because Truth is the end of the intellect. The intellect desires Truth, and possesses the essence of the intellect – i.e. knowledge – insofar as it possesses the Truth. The more Truth the intellect possesses, the more the intellect. The more the appetite possesses the Good, the less the appetite.
Question 17 discusses Falsity. Aquinas does not make any remarkable statements. He simply observes that falsity is opposed to Truth, and consists of stating that something is what it is not, or stating that something is not what it is.
In Question 84, Aquinas posits that the soul needs the body in order to gain knowledge. He even uses language that is very similar to Locke’s blank slate theory – i.e. the brain is a blank slate, and we acquire knowledge through sensory experience. This is contrary to Plato’s argument that the body is a hindrance to the soul’s ability to attain knowledge. Plato states that the soul can only attain Truth when it is liberated from the body. But Aquinas provides very strong evidence to support his counterargument. He writes that a man who is blind from birth does not possess any notions of colors. If Plato was correct about every soul possessing notions of everything, the blind man who is ignorant of colors provides a clear refutation. In defense of Plato, a blind man has never seen the color blue, but this does not necessarily mean that he cannot comprehend that there are different wavelengths of light that produce different effects upon the vision of those who can see. Perhaps the blind man can even “see” colors during his contemplation of the Good.
Question 85 discusses the process by which we attain knowledge. Aquinas posits that we attain knowledge of universal concepts by abstracting ideas from the impressions we receive from physical objects. For example, we attain knowledge of ‘red’ by abstracting the color from various sense impressions that we receive from red objects – such as apples. Once again, this argument contradicts Plato, who argues that the knowledge of universal concepts are innate and that we understand the physical world by comparing the various physical objects with our innate universal ideas.
Question 86 investigates the limits of our knowledge. Aquinas states that we cannot comprehend infinity itself, but we can attain some knowledge of it through our conception of infinite succession. Likewise we cannot know the future itself, but we can have some knowledge of the future through our knowledge of causal relationships.
There is nothing in either question 87 or 88 that is very remarkable. Aquinas states that we know that we have a soul because we perceive the soul at work – i.e. we perceive ourselves understanding and coming to know certain truths. But we cannot have a perfect understanding of immaterial substances because immaterial substances are very different from the material substances by which we come to understand anything.
“If questions be put in an orderly fashion they proceed from universal self-evident principles to what is particular. Now by such a process knowledge is produced in the mind of the learner. Wherefore when he answers the truth to a subsequent question, this is not because he had knowledge previously, but because he thus learns for the first time. For it matters not whether the teacher proceed from universal principles to conclusions by questioning or by asserting; for in either case the mind of the listener is assured of what follows by that which preceded.”
“God is called infinite, because He is a form unlimited by matter; whereas in material things, the term ‘infinite’ is applied to that which is deprived of any formal term. And form being known in itself, whereas matter cannot be known without form, it follows that the material infinite is in itself unknowable. But the formal infinite, God, is of Himself known; but He is unknown to us by reason of our feeble intellect, which in its present state has a natural aptitude for material objects only. Therefore we cannot know God in our present life except through material effects. In the future life this defect of intellect will be removed by the state of glory, when we shall be able to see the Essence of God Himself, but without being able to comprehend Him.”