In order to understand what it means to be human we must begin by studying humans. We need to see what they are. The approach that I am suggesting is an empirical approach to knowledge. For example, in the Summa Theologiae Thomas Aquinas waits until Question 12 to discuss how it is that mankind comes to knowledge, albeit imperfect knowledge, of God. He has already discussed Gods unity, eternity, immutability, immanence, infinity, goodness, perfection, simplicity, and existence. Having discussed these issues he then looks back upon the knowledge that we acquired, and asks the question, "How did we attain this knowledge?" To many philosophers, and theologians, this order may seem counter-intuitive. Those who might think so are tempted to say, “How can you even talk about what God is like until you have established that you can know what God is like and how it is that you come to such knowledge?” This type of thinking is exactly why many contemporary theology books begin with Bibliology and Methodology. They wish to set down the basis for our knowledge of God, to prove that we can in fact know him and how we come to knowledge of him, before they begin talking about what God is like.
This philosophical attitude, by which the philosopher or theologian feels that they must prove the possibility of, and manner of, attaining knowledge in theology, is paralleled (and most likely inspired) by a similar attitude in most philosophical endeavors since Descartes. In his book, The Unity of Philosophical Experience, Etienne Gilson shows that Descartes, seeking a sure foundation for knowledge, over against the skeptical problems, decided to begin with the skeptical problems. That is, before he began discussing reality he decided that it was necessary to proof that we could know reality. He answered the skeptical problems with an argument reminiscent of Augustine’s argument against the skeptics, and then built his entire philosophical system on that foundation. If I doubt that I exist, I at least know that I doubt; if I know that I doubt then I know. If I know, then I exist. However, as Gilson points out, “Every one is free to decide whether he shall begin to philosophize as a pure mind; if he should elect to do so the difficulty will be not how to get into the mind, but how to get out of it.”
The skeptical problems of Descartes, and his methods of getting around them, have influenced philosophers, in one way or another, since Descartes first began philosophizing with the skeptical problems. In fact, if you look at most contemporary textbooks for epistemology you find just this order: either you begin with the skeptical problems or you begin by seeking justification for knowledge. Both of these methods begin with knowledge, and then try to prove that we can know some sort of mind-independent reality, in some way.
A comment by Étienne Gilson in his book, Réalisme Thomiste et Critique de la Connaissance, is particularly a propos at this point, “Ou bien on partira de l’être en réaliste, et l’on aura aussi la connaissance, ou l’on partira de la connaissance en idéaliste critique, et l’on ne rejoindra jamais l’être.” Descartes' problem, and the problem of any philosopher who wants to begin with the critique of knowledge, is that he is unable to get from the existence of his own intellect to the existence of the real world. As Gilson attempts to show, in his book The Unity of Philosophical Experience, ever since the time of Descartes philosophers have been trying to get back to the real world, however it seems that they have been relatively unsuccessful. Gilson suggests a different approach to knowledge, “Ce qu’il faut, c’est qu’au lieu d’être une condition de l’ontologie, l’épistémologie croisse en elle et avec elle, étant à la fois explicatrice et expliquée, la soutenant et soutenue par elle, comme se soutiennent mutuellement les parties d’une philosophie vraie.”
As we have seen, the thinking of contemporary theologians and many philosophers of epistemology is clearly inspired by the critical philosophers who think that we must establish the fact that we can possess knowledge before we can talk about what we think that we know, and how we know it. One of the problems with such an approach is that there is no such thing as "knowledge in a vacuum". Knowledge, in order to be knowledge, must have an object. Which is to say, you have knowledge of something. “The critical philosophers—following the program of Descartes—attempt to subject the instruments of knowing to a searching analysis in order that they might establish (if possible the reliability of human knowledge itself; once they have established this reliability to their own satisfaction, they turn to other philosophical issues; they begin with the evidence of thought; they terminate (perhaps) in the evidence of being.” These philosophers set out on a journey that can only end in skepticism.
We, however, will begin by studying the human person. Afterwards we will be able to ask how it is that we came to knowledge of the human person; then we will be able to tweak the method, and use it to come to even deeper knowledge of what it means to be a human person.
Thomas Aquinas, Summa Theologica, trans. Fathers of the English Dominican Province (1948; repr., Notre Dame, IN: 1981), 1:48-59.
Etienne Gilson, The Unity of Philosophical Experience (1937; repr., San Fransisco: Ignatius Press, 1999), 156-57.
See for example: Louis P. Pojman, What Can We Know?, 2nd ed. (Belmont, CA: Wadworth/Thomson Learning, 2001), v. Robert Audi, Epistemology: A Contemporary Introduction to the Theory of Knowledge, 2nd ed. (2003; repr., New York: Routledge, 2004), contents, vii.
Étienne Gilson, Réalisme Thomiste et Critique de la Connaissance (Paris : Librairie Philosophique J. Vrin, 1947), 156. “Either we begin with being as a realist, and we will also get knowledge, or we begin with knowledge and we will never arrive at being.” [Translation is mine.]
Étienne Gilson, Le Réalisme Méthodique (Paris : Pierre Téqui, 1936), 15. “What must happen, is that instead of being a condition for ontology, epistemology must grow in it and with it, at the same time explaining and being explained, supporting it and being supported by it, just as the parts of a real philosophy are mutually supportive.” [translation is mine]
Frederick D. Wilhelmsen, Man’s Knowledge of Reality: An Introduction to Thomistic Epistemology (Englewood Cliffs, NJ: Prentice-Hall, 1956), 17-18.