I happened to notice that sometime later, a commenter had critiqued this axiom, thus:
Don't forget genetics. That determines what we can sense, literally, and how it can be sensed.
Also, the vast majority of what we do sense never reaches consciousness, and our decisions are rarely rational. Saying that we're sentient rational beings is a step or two beyond generous. That we're so prone to flattering ourselves for qualities we mostly lack says something about the quality of our subjective judgement.
Now I don't know the commenter, and I realize the thread at unBeguiled is cold, but the impressive illogicality of the critical comment merits a closer look. And I mean that. For me, a major element of Scholastic anthropology is at stake if this commenter's critique had any merit, and, therefore, his jab at hylomorphism ought to be skewered so that similar failures of logic have that much less of a voice in the debate. I will also conclude by noting a disastrous irony in the critique, which I will call "a klu(d)ge attack", in reference to the notion, à la Gary Marcus, that the human cognitive system is an ad hoc, clunky, ultimately unreliable quick-fix patched together just well enough by crude evolutionary duct tape and self-congratulatory human confabulation to let us survive childhood and inseminate a viable uterus.
But enough romance.
The first claim in this kludge attack is as easily dispensed with as it was dispensed, since it merely restates the Scholastic axiom. The point of the axiom is that our intellectual contact with the world is rooted in our created biological nature. Adding the term "genetic" to this nature does little more than sharpen its image.
The second claim is more ambitious, mo' bigger, and therefore falls mo' harder. It is an attempt to show that the axiom nihil est in intellectu quod non prius fuerit in sensu is wrong. It is attempting to show that the cleft between our senses and our intellect is wider than the Scholastic axiom permits. To grasp how badly the kludge attack misses the mark, consider this modus tollens syllogism:
Nothing is digested by your stomach that is not first ingested by your mouth.
But this bubble gum is in your mouth and not in your stomach.
Therefore, you have a deficient digestive system.
The kludge attack displays a parallel (il)logic:
Nothing is conceived by the intellect that is not first perceived by the senses.
But some sensory data are in the human senses and not in the human intellect.
Therefore, humans possess a rationally deficient intellect.
The second prong of the kludge attack rests on a massive logical confusion. The Scholastic axiom says that what is (normally)* in our intellectual grasp is first of all in our sensory grasp. It does not, however, state that whatever is in our sensory grasp is in our intellectual grasp. The kludge critique, however, assumes the axiom does entail the second claim, which is why it notes cases where what is in our sensory grasp is not also in our intellectual grasp. This is true enough, and is basically what the Scholastics meant by saying that humans have not only a vegetative (biotropic) and animal (semiotic) soul, but also a rational (intellectual) soul. The critique fails, then, by trying to refute Scholastic anthropology with a distinction it already accepts.
The primary intrinsic organizing principle (or soul, anima, morphē) of human life is a "vegetative" power. This metaphysical substratum keeps our lungs breathing and hearts pumping, propels us to seek warmth and nourishment, compels away from crushing pressures and pains, and so forth. This is our "brain stem soul." A second intrinsic organizing principle of human life is the animal power. This energizes us to interact with other living entities, to seek more distant desires (like that water hole we recall from a few days earlier), to emit sounds of distress and interest, and so on. This is our "cerebellar soul." The third intrinsic organizing principle of human life is the rational soul, which is what enables us to name objects, to organize large-scale plans based on immaterial desires, to reprioritize and redefine our values based on our social commitments and linguistic ideals, etc. It is by the intellect that we "know" what a "tree" is, but it is by the senses that we know this or that tree. Without the intellect, we could never know a "tree" as something metaphysically distinct, for we cannot perceive the particular (sensory) without a simultaneous conception of the universal (intellectual) in any particular. Nor can we directly intuit metaphysical essences apart from direct sensory contact. We know the universal, therefore, in the particular and the particular by the universal.
This delicate balance between empirical and rationalist cognition is what makes Scholastic anthropology so robust. There is nothing disturbing for an Aristhomist to hear that much of what enters our sensory database does not also inform our rational actions. Most of life is driven by the autonomous vegetative and animal powers of man, and it's just as well, since if the lower two powers in man had to be vetted by the rational soul moment by moment, humans would suffer a cognitive overload.
The third point worth mentioning is that the denigration of our rational nature inherent in this "kludge cudgel" is self-destructive. Here we have a commenter denying the efficacy of human reason… by means of human reasoning. He is, in other words, deploying a rational argument against rational argumentation. Hence, as G. K. Chesterton writes in his preface to Fulton J. Sheen's God and Intelligence in Modern Philosophy (New York: Image Books, 1925), "in the modern world generally, the Catholic Church comes forward as the one and only real champion of Reason" (p. 7). "The Church is larger than the world," Chesterton continues,
"and she rightly resisted the narrow rationalists who maintained that everything in all the world could be approached in exactly the same way that is used for particular material things in this world. But she never said those things were not to be approached, or that reason was not the proper way to approach them, or that anybody had any right to be unreasonable in approaching anything. She defends the wisdom of the world as the way of dealing with the world; she defends common sense and consistent thinking and the perception that two and two make four" (p. 7).
Chesterton's point takes on even greater significance when we recall how the commenter's jab at human reasoning is, as I say, itself a specimen of human reasoning. "Who knows," Chesterton mockingly pantomimes an irrationalist like Ibsen, "that two and two do not make five in the fixed stars?" (p. 8) The humble air of critical worry, in both Ibsen's worry and our commenter's anti-rationalism, is as initially admirable as it is ultimately incoherent. "If you are not sure there are any fixed facts" Chesterton goes on, "how do you come to be sure there are any fixed stars?" (p. 8) In other word, the ability to detect errors in human reasoning presupposes the reliability of our rational examination of those errors.
We obviously are not merely blind kludges-with-legs, since we can transcend our kludgey limitations well enough to discover, trace, and remedy them. This dynamic captures the vitality of Aristhomistic epistemology, insofar as Artisthomism maintains a healthy balance between the sensory limits of human reasoning and the intellectual advances humans can make over their sensory limitations. For this reason I call the largely anti-rationalist kludge psychology of modularity-evolutionary psychology biological Kantianism (cf. the lower sections of this post on Lakoff and Johnson). Just as Kant's distinction between phenomena and noumena and his attendant denial that we can know the noumena presuppose an adequate enough knowledge of both terms to know where one begins and another ends, so biological Kantianism presupposes the reliability of our cognitive abilities in the very act of deconstructing them.
Chesterton's whimsically devastating comments dovetail with a point Sheen makes a few chapters later in God and Intelligence. Contrasting the contemporary (ca. 1925) intuitionist-pragmatist form of theology with the classical-intellectualist form of theology, Sheen notes the latter "began with the world––not the world of internal experience but the external world of movement, contingency, varied perfections, efficient causality and finality. Its point of departure was extra-mental. The source of its proofs was in the open air" (p. 43). This emphasis on the externality of our cognition is all of a piece with the Scholastic axiom nihil est in intellectu quod non prius fuerit in sensu, since that axiom without question directs man to look outside the limits of his own skin and his own dim inner intuitions of the world, and to remain in humble connection with the world as it comes to him via the sensory systems endowed to him by his Maker. A sounder metaphysical basis for empirical science could hardly be fathomed, and, in fact, has not yet been fathomed.
* * *
* I say "normally" since Catholic mystical theology acknowledges "infused knowledge." Infused knowledge is anything known by a person––say, a foreign language, the hour of someone's death, the exegesis of a biblical passage, etc.––that does not enter his intellectual conceptions by means of the normal sensory-inductive process. Despite its insistence on sensory intellection, Aristhomism finds infused knowledge no more bizarre––nor any less in need of a special "outside" grace––than if a doctor surgically implants a meal into a patient's stomach after a major craniofacial operation.