In his 1996 book The Last Word philosopher Thomas Nagel makes what is nowadays an extremely unfashionable argument – namely, a full-blooded defense of a Platonic/Cartesian understanding of reason over against various pragmatist and postmodernist subjectivisms or skepticisms. Along the way he also raises questions of a theological nature about what it implies about the universe that it contains creatures endowed with the capacity to aim at universality in their understanding of things.
The kinds of subjectivism that Nagel wants to refute are those that seek to call into the question the universal validity of reason by reducing it to some less universal feature of our experience such as our personal psychology, or our cultural or linguistic practices. The idea is that what we take to be universal standards or methods of rationality are “really just” facts about the way we happen to think, because of our biological or psychological constitution, or our cultural or linguistic situation. The variety or contingency of these (biological, psychological, etc.) factors is then taken to cast doubt upon reason as a way of arriving at truth full stop (as opposed to beliefs that are merely “true for us”).
Nagel addresses several different areas where reason is employed, but the same basic thread of argument runs throughout. Essentially Nagel’s argument is that every attempt to reduce reason to psychology, or culture, or linguistic practice, or what have you is an attempt to reduce the more fundamental to the less fundamental. This is because every subjectivist account of reason can only appear to us as a rival hypothesis which has to be assessed rationally, and so can never offer reasons for a global skepticism about reason (though there can obviously be grounds for skepticism about particular uses of reason). “Whether one challenges the rational credentials of a particular judgment or of a whole realm of discourse, one has to rely at some level on judgments and methods of argument which one believes are not themselves subject to the same challenge: which exemplify, even when they err, something more fundamental, and which can be corrected only by further procedures of the same kind” (p. 11).
Logic is the easy case. It is literally impossible, Nagel says, to entertain the thought that, say, 2+2=5 or that modus ponens is not a valid rule of inference (allowing that one understands the concepts involved). Nagel out-Descartes Descartes here in contending that pace Descartes’ skeptical thought experiment in the Meditations, it really isn’t possible for me to doubt the elementary truths of logic or arithmetic. This is because I literally can’t conceive of what it would be for them to be false and any argument that I could construct to show that I can doubt them would itself rest on those elementary truths. Far from being a merely contingent feature of the way we happen to think about the world, logic is the inescapable foundation of all our thought.
Science, understood as the search through rational inquiry for patterns of order in the external world, is less certainly founded, but Nagel’s argument against global skepticism or subjectivism about such an enterprise is not fundamentally different. Obviously we can, and have been, mistaken in taking particular scientific theories to be true descriptions about the world; that’s not what’s at issue. What is at issue is the entire enterprise of seeking to understand the order of the external word. The subjectivist challenge is that, far from discovering order, we impose order on the “blooming, buzzing confusion” of experience (to use William James’ expression). We need order, and so we create it, either because of the kinds of beings we are (the Kantian explanation) or because of our particular cultural or linguistic practices.
But as Nagel makes clear, the subjectivist explanation is just a rival explanation of the way the world is that makes subjects and their various perspectives the fundamental truth about the way things are. But far from being self-evident, this rival theory has to be assessed alongside the theory that we are selves inhabiting an external world whose order we seek to discern. “A subjectivist interpretation of reason thus becomes just another hypothesis about the world and our relation to it, and that makes it subject finally to rational assessment, so that the aim of rational assessment of our beliefs turns out to be unavoidable” (p. 92). Whatever perspective we try to use to discredit the universality of reason – biology, psychology, language, culture, whatever – is itself always subject to rational assessment and critique. Reason is always more fundamental than any of these other discourses, and to try to use them to debunk reason itself is like sawing off the branch on which you’re sitting.
None of this is to deny that we are situated in particular physical, social, and cultural contexts that condition the way we see the world. It’s just that the aspiration of reason is always toward universality; if I think x constitutes a good reason for y, I think that it would constitute a good reason for anyone in similar circumstances. Much of the “postmodern” critique of reason seems at times to be an extended exercise in committing the genetic fallacy. Offering a particular account of why one has a certain belief (e.g. because of one’s social or cultural location, upbringing, etc.) does not settle the question of its truth.
This however raises an important question that Nagel addresses in the final chapter, “Evolutionary Naturalism and the Fear of Religion.” The question is how to account for the fact that certain contingent bits of the universe (us) are endowed with a capacity to have thoughts which have universal validity. Interestingly, Nagel, an avowed agnostic, says that the attempt to explain this fact by appealing to evolution “has always seemed to me laughably inadequate” (p. 75).
To be continued…
A Thinking Reed 
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