In Rationality and Logic, Robert Hanna has one central claim: “logic is cognitively constructed by rational animals, in the sense that all and only rational animals … possess a cognitive faculty that is innately set up for representing logic … it contains a single universal ‘protologic.’” (Rationality and Logic xiii). This latter claim is “the logic faculty thesis” (Rationality and Logic xiii). Logic is about “schematizable language [a syllogism] in which some sentences [premises] are asserted and another sentence [the conclusion] is asserted that is held to follow from the others” (Rationality and Logic xv). Therefore, logic itself is “the science of the necessary relation of consequence” in that the “necessary connection between the premises and conclusion of a valid argument is the relation of consequence” (Rationality and Logic xv). Without logic, what I have called non-logical pluralism arises: anything (any conclusion) can follow from anything (any set of premises). Logic is the only refutation to non-logical pluralism in that it defeats the claim that anything can follow from anything by demonstrating that mere inference is not a sufficient condition for justifying the inadvertent assertion contained in non-logical pluralism that is the elimination of necessity, of necessary connection, of the relation of consequence.
This brings us to a new question: “What is the nature of logic?” which is to ask “Why is our understanding of logic justified?” This could be understood as the logocentric predicament, but I would be wary of this, for “our understanding of” is somewhat problematic in the face of skeptical rebuttal, i.e., the skeptic questioning the non-skeptic until the non-skeptic is reduced to a state where they cannot justify their presupposition. The real question is “Why is logic justified?” The supposition of the subject is not acceptable in terms of what we are trying to carry out. To even be able to logically warrant the subject’s existence, one must suppose logic, and therefore the circle just has another implicit step.
Now, one could say, “If there are rational animals, then logic has a basis.” This would eliminate any supposition of the subject’s existence, but nevertheless, the more rigorous procedure entails minimizing the number of if-statements. Even then, would the rational animal’s mind make logic justified? It would explain why we think logically, but why ought we think logically? Hanna’s protological logic faculty seems to fall to the is-ought gap. But, one could argue that we have to suppose the protologic that is the logic faculty because we are using logic to point out how the protologic is not completely logical itself. In this sense, Hanna has created a transcendental argument where the necessary condition for logic is the protological logic faculty, and therefore any use of logic supposes the protologic, and because the protologic itself is not completely and necessarily logical, it can elude the problems of vicious circularity and infinite regress, as those are logical operations. Therefore, any theory of logic supposes the protologic. Dennis Schulting, in response to Hanna’s proposition of the protologic, argues,
Thought, or more precisely, the principle that constrains thought, namely the original synthetic unity of apperception, is the a priori ground of logical and conceptual truths as well as non-logical truths, which are about objects in the world, or anything that is not logically or merely conceptually analysable. (“Good-Bye To Analytic Philosophy And All That” 9)[1]
Hanna doesn’t disagree and argues that what Schulting has just said is “perfectly consistent with the general solution to The LP problem that I [Hanna] worked out in Rationality and Logic” (“Good-Bye To Analytic Philosophy And All That” 9). Again, though, Schulting supposes thought, he supposes the subject or at least something.
Moving on to pure general logic, for a moment, Hanna says something that is to intrigue us most certainly:
I interpret pure general logic’s generality in terms of logical truth’s necessary underdetermination by every possible domain of truth-making objects, including empty domains as a limit case, along the lines of Tarski’s model-theoretic definition of logical truth, but not as abstracting logic away from objects. (“Good-Bye To Analytic Philosophy And All That” 11)
So, here, Hanna is obviously speaking about how pure general logic isn’t restricted by objects and those domains that (truth-making) objects lie within. But, in regards to transcendental logic, Hanna says,
Then transcendental logic requires, as its special domain of objects, all the objects of actual or possible human experience, that is, all the experienceable worlds. (“Good-Bye To Analytic Philosophy And All That” 11)
Transcendental logic is restricted by the object and in fact supposes an object in that transcendental logic does not exist if objects do not. But, pure general logic does not suppose such a thing because pure general logic holds equally over those domains wherein there is something and those domains wherein there is not, i.e., “there” “is” nothing. Hanna, then, furthers the real nature of transcendental logic and the number of presuppositions it has:
Hence transcendental logic also specifically presupposes all the transcendental conditions for the possibility of human experience — the pure forms of sensibility, the schematized Categories, the transcendental schemata of the imagination, and the original synthetic unity of apperception — whereas pure general logic does not. (“Good-Bye To Analytic Philosophy And All That” 11)
Hanna then makes an unusual turn: “I hold that [the protological logic faculty] is metaphysically prior to all logic, whether pure general logic, transcendental logic, or any other kind, and grounds them all” (“Good-Bye To Analytic Philosophy And All That” 11). This is of course a metaphysical presupposition, but would Hanna not say that my logical inference, which was that what he has just put forward supposes its own metaphysical existence, supposes the protological logic faculty. Would it, therefore, follow that because logic and its employment suppose the protologic which is contained in rational animals’ facilities, a rational animal must necessarily exist as logic is being employed? Of course, though, this supposes that “logic is being employed” which supposes the skeptic or the non-skeptic’s existence. Must one then warrant that they exist and employ logic before they can “warrant” the protologic? This may be the case, as even Hanna himself admits “I am assuming that the existence of rationality and human rationality are primitive and irreducible facts” (Rationality and Logic xix). Let us return to this question of warranting the subject’s existence later. Let us say if rational animals exist, then the protological logic faculty therefore exists, and the very presupposition of logic, the logocentric predicament, is itself a proof of the protologic’s existence. Like I said earlier, even if we cede to Hanna’s metaphysical (and epistemic) assumptions, he still has an ethical supposition: “Why ought we think logically?” As Hanna says, “To say that logic is normative is to say that humans ought to reason soundly or validly” (Rationality and Logic 203). The view of logic’s normatively I’m inclined to agree with is the view that logic is intrinsically categorically normative which is basically to say “[l]ogic tells us how we ought to reason or think in every possible set of circumstances because this is required by the nature of rationality” (Rationality and Logic 204). One may argue that this falls into the naturalistic fallacy. But, this is not the case because, if we follow Kant’s understanding of logic as intrinsically categorically normative, then we can say that “moral prescriptions inherently fail to be strictly determined by either human interests or the natural facts” (Rationality and Logic 208). But, it is not just logic that is normative, but the protologic too is normative: “the protologic, as a set of logical principles and concepts for constructing logical systems, is inherently normative precisely insofar as it is a set of schematic permissions to construct logical systems in just these ways and no others” (Rationality and Logic 209). Hanna furthers, “To say that logic is intrinsically categorically normative is simply to say that logic is rationally humanly inescapable, or at least to say that the protologic is rationally humanly inescapable” (Rationality and Logic 212). The categorical imperative expresses itself through protologic: “Think only according to those processes of reasoning that satisfy the protologic” (Rationality and Logic 213).
But where do we go from here? I take an issue with the protologic simply because the only reason it seems to be binding is that Hanna says it is. Or rather, the only reason the idea of a logic faculty seems binding is that Hanna tells us that it is the protologic. But, how does the logic faculty make logic any less circular? Okay, we know logic has a starting point in that it is cognitively and continually constructed, but again that logic has such a starting supposes that this is the case. By this, I mean that Hanna is most definitely stuck in a metaphysical presupposition here. The logic faculty cannot be the protologic until it itself supposes nothing, for would that which it is based upon not be the protoprotologic, or something like that? One could say that I am begging the question, though, because I’m supposing the protologic needs a foundation. To this, all I would say is that it cannot be justified as the protologic if it needs a foundation, and it is clear the idea of the logic faculty certainly has presupposition in that it itself is a metaphysical presupposition. That is the main issue I have with Hanna’s Rationality and Logic, the metaphysical presuppositions. Cognition, Content, and the A Priori, on the other hand, is quite the book in its ambition which Rationality and Logic only had a fraction of.
The theoretical primitive, in my opinion, is a much more convincing notion than the notion of protologic is, though these two notions sometimes are intertwined.
Note
[1]: I hope to go over Schulting’s solution to the logocentric predicament in extreme detail in the future or maybe in this essay.
