That philosophy consists of the love of wisdom and, therefore, the constant search for truth, is well known. However, before dedicating ourselves to philosophy, perhaps we should consider the very nature of truth. That is, we must question whether truth is possible and, if we can accept some degree of truth, we must elucidate what it is and where its validity lies.
Of course, we can accept that judgments like “it seems cold to me” are beyond discussion, since there is little to discuss about what seems to me within the realm of subjectivity.
However, when we speak of truth, it seems that judgments based on shifting, subjective impressions, so subject to mutable circumstances, are insufficient. The cold I perceive can soon change, and I might perceive heat. Furthermore, my sensory perception is not always infallible regarding the objectivity of the world. Therefore, we can understand that this is not the kind of truth we seek.
St. Augustine expresses something similar in his Against the Academics. However, I am interested in reflecting on the argument concerning truth that appears in On Free Will. It is found in Book II, and covers approximately chapters VII-XV. In these few paragraphs, we find one of the most fascinating —and, curiously, least discussed — discussions about truth in the history of philosophy.
The holy Bishop of Hippo begins by showing that the truth sought when pursuing wisdom is such that everyone who is in the truth can observe it at the same time and in the same way.
It is evident that we are dealing here with a notion of truth that transcends the information that the senses can give us, since Saint Augustine refers to an eternal and necessary truth.
Our author finds an example of such a truth in arithmetic. While my bodily sensations are constantly changing, I can find absolute certainty in a judgment like “three plus seven equals ten.”
This truth cannot be overturned by the skeptic; it does not depend on the subject who thinks it—since it offers a clear normative criterion, as we know that the judgment “three plus seven equals eleven” is wrong—nor on the senses, since the arithmetic relationship is grasped directly by the mind.
Furthermore, unlike bodily sensation, this truth is incorruptible. We find, then, that the ideal model of truth for Saint Augustine involves mathematics, as Plato had already thought.
How can the human mind discover and understand these eternal and necessary truths ? Since it has been demonstrated that their foundation cannot be found in the senses, the question arises whether they are sustained by the human mind itself. And Saint Augustine answers clearly: no.
The saint points out that truth is “more sublime than our spirit and our reason” (De Lib. Arbitr. II, 13, 35), precisely because our understanding is also changeable, while the truths of arithmetic remain eternal and immutable.
We would say, then, that only an eternal and immutable understanding can be the foundation of these truths that man grasps, although not always infallibly, through his own reason.
This mind capable of conceiving mathematical reasons must be as eternal as they are, and with this it becomes clear that, for Saint Augustine, the possibility of truth requires the existence of God, whose mind is not only the ontological support of truth, but identical to it.
Thus we understand that every time man finds the truth he is finding, strictly speaking, something superior to himself with which he is, however, closely united.
Defining the exact nature of this union would take us beyond the scope of this text, as Augustinian scholars have offered numerous interpretations of this doctrine. In any case, we can provide some essential points regarding how the Bishop of Hippo explains it.
In his commentary on Psalm 118 (Serm. 18,4) he writes: “God also made man’s rational and intellectual mind, through which he might perceive his light.” Here we encounter the Augustinian doctrine of illumination. Just as the sun illuminates the objects of sight, divine illumination illuminates those of the intellect.
It is important to point out that this does not mean that human understanding, through this illumination, contemplates the idea itself as it exists in the mind of God, nor that God infuses ideas directly into the human mind.
Nor does sunlight create images of objects; it merely makes them visible. Therefore, illumination does not instill in us the concepts of “three” and “seven,” but rather allows us to see that the relationship between them when we add them together is eternal and necessary.
In conclusion we can affirm that, without being able to have direct experience of the divine essence in this life, we do distinguish the necessary, immutable and eternal relationships between the concepts of true judgments.
And this cannot come from our senses or our mental projections, but from an eternal source. We must therefore consider the relationship of our soul with God to explain something as elementary, yet as fascinating, as the discovery of arithmetic truth, undeniable in the experience of exercising our natural reason, which reveals the theological foundation of epistemology.
And this light, distinct from understanding itself—contrary to some Thomistic interpretations—makes possible the encounter with truth within the frailties of the creature’s intellect. It seems that only in this way can that search, so concisely formulated by Saint Augustine in his Soliloquies (II, 7), be satisfied:
A: I have prayed to God.
R: What, then, do you want to know?
A: Everything I have asked for.
R: Summarize it briefly.
A: I want to know God and the soul.
R: Nothing more?
A: Nothing more.
