Scratch a philosopher, find a reductionist revolutionary. Thales thought he’d shake up the world by claiming everything was made of water, a resourceful guess by a sixth-century-BC thinker stuck in a port city. Pythagoras declared that all things consisted of numbers because harmonies and ratios did. Heraclitus judged the sole primary element to be fire, then made sure we had enough rivers to douse it in an emergency.

That monomaniacal spirit, obsessed with balancing the world on one foot or idea, meanders through the Western philosophical tradition, stopping at major stations such as Spinoza’s sole substance of “God/Nature” and local curiosities like Bergson’s élan vital. Thus it has ever been: If you would stir tumult in the canon, surround a concept, then exalt it, make it over or drive it out of the temple, whipping the mangy beast if necessary.

In these fin de millénaire dog days for philosophy, “reason” presents an especially inviting conceptual target. Humiliated and marginalized by twentieth-century politics and war, belittled by psychoanalysis, stripped of its capital letter by everyone except the Germans, it hobbles along in the humanist vocabulary, mainly surfacing in musty older-generation conversation. (“Won’t he listen to reason?”) Even intellectuals who treasure its Enlightenment glory days treat reason like a rickety emeritus, worthy of deference during chance encounters but not of mention in one’s current work. Many philosophers and cognitive scientists exclude it from their books and indexes, ignoring it like some now embarrassing cousin of phlogiston.

So the first thing to say about Donald Calne, George Lakoff and Mark Johnson is that they buck those who refuse to listen to reason and attempt to put it back at center stage, if not atop its old pedestal. They treat “reason” not just as an idea that still matters but as perhaps the proper cynosure of philosophy, rightly understood. Their voices exude familiar revolutionary commitment: Listen to my big ideas, because they may change your thinking about thinking forever.

Calne speaks in the softer register. A Vancouver neurologist who specializes in neurodegenerative disorders, he comes not to bury reason in the new semantics of neurons, synapses and the anterior cingulate sulcus (where Francis Crick locates free will) but to raise it out of wet matter and see what’s left. Reason, Calne assures, may still be regarded as a psychological “faculty” in traditional style, so long as we recognize that it’s “a biological product” and understand that we’re “motivated by instinctive urges and emotions linked to cultural forces–reason is their servant and not their master.” Calne argues that modern neurology gives reason no role in setting our goals: It deals with “how” issues, thus explaining why ours is not to reason “why.” It is “simply and solely a tool” fashioned by evolution, a capability that “cannot assign or control the purposes to which it is put,” something we use “to get what we want, not to choose what we want.”

Lakoff and Johnson deliver their goods in preachier language, particularly when taking swings at philosophy as a discipline. This is unquestionably their “big trade book,” coming after the influential work on metaphor they developed together in Metaphors We Live By (1980) and More Than Cool Reason (1989), then elaborated separately in Lakoff’s Women, Fire and Dangerous Things (1987) and Moral Politics (1996), and Johnson’s The Body in the Mind (1987). Philosophy in the Flesh aims to mine the gold of that corpus for the well-educated nonspecialist, to trumpet for the sentinels of lay culture that a Cartesian-sized turn in philosophy is here (however anti-Cartesian its bent).

Lakoff, a distinguished professor of linguistics at the University of California, Berkeley, and Johnson, head of the philosophy department at the University of Oregon, begin with “three major findings of cognitive science”: first, that the mind “is inherently embodied”; second, that thought “is mostly unconscious”; and third, that abstract concepts “are largely metaphorical.”

“More than two millennia of a priori philosophical speculation about these aspects of reason are over,” the two declare in their introduction, for these findings “are inconsistent with central parts of Western philosophy. They require a thorough rethinking of the most popular current approaches, namely, Anglo-American analytic philosophy and postmodernist philosophy.”

The best way to see why is to examine how these findings alter the concept of reason. “Reason,” the authors state, is still viewed as “the defining characteristic of human beings.” It includes “not only our capacity for logical inference, but also our ability to conduct inquiry, to solve problems, to evaluate, to criticize, to deliberate about how we should act, and to reach an understanding of ourselves, other people, and the world.”

Reason, according to cognitive science, however,

is not disembodied, as the tradition has largely held, but arises from the nature of our brains, bodies, and bodily experience…. The very structure of reason itself comes from the details of our embodiment. The same neural and cognitive mechanisms that allow us to perceive and move around also create our conceptual systems and modes of reason. Thus, to understand reason we must understand the details of our visual system, our motor system, and the general mechanisms of neural binding.

Reason, in short, is not independent of perception and bodily movement, and neural associations take place between perceptual and inferential acts. Our bodies and brains determine the kinds of categories we will form for making sense of experience. So, for instance, our spatial notions of “in front of” and “in back of” derive from our being creatures with fronts and backs who project that distinction onto objects like cars and TVs. Reason is also “evolutionary, in that abstract reason builds on and makes use of forms of perceptual and motor inference present in ‘lower’ animals.” That discovery “utterly changes our relation to other animals and changes our conception of human beings as uniquely rational.”

According to Lakoff and Johnson, reason is therefore not universal in the sense of being transcendent–it is “not part of the structure of the universe.” That led some early readers to tag the pair as “relativist” or even “multiculturalist,” which they deny. They acknowledge that reason may be widely or universally (if contingently) shared by humans because of our similar bodies, a position they call “embodied realism,” as distinct from the philosophical tradition’s “disembodied realism.” As such, reason is not “completely conscious, but mostly unconscious.” It is “not purely literal, but largely metaphorical and imaginative,” not dispassionate but rather “emotionally engaged.”

If all this is true–and Philosophy in the Flesh attempts to demonstrate it by applying “embodied realism” to classic metaphysical puzzles (such as time and causation) and the history of philosophy itself–out goes much of our philosophical baggage from “major classical views of what a person is.” Goodbye to the Cartesian subject, with a mind independent of the body. So long to Kant’s radically autonomous person, because reason doesn’t transcend the body. Adieu to the ideal utilitarian agent, since embodied humans don’t control most of their reasoning, let alone the part that maximizes self-interest. Equally dispensable is the fashionable image of the mind as purely computational–fungible software working on fungible hardware–because real, embodied minds do not merely manipulate empty symbols.

It’s a heady onslaught of ideas, and Lakoff and Johnson deserve enormous credit for their work, both over the years and in this cagily disguised textbook. For all the repetition and jargon that make the volume a homely “container” for marvelous ideas, they’ve taken momentous insights associated with Continental thinkers from Fontenelle to Derrida–the most important being that metaphor suffuses all supposedly abstract philosophical language–and explored them in a characteristically American, empirical spirit. They’ve marshaled heaps of scientific and social-scientific data, and schematized them to a degree that would have fatigued a lightly empirical concept reviser like Foucault and would seem ploddingly dull to a skeptical ironist like Derrida.

Lakoff and Johnson’s dissections of what they call our primary metaphors–paradigms like “Affection is Warmth” (“They greeted me warmly“) or “Happy is Up” (“I’m feeling up today”)–significantly illuminate how we form abstractions by grafting physical phenomena onto subjective experience. Whereas study of metaphor remained a back alley of philosophy for decades, their work, and landmark anthologies such as Andrew Ortony’s Metaphor and Thought (1993), mean no respectable philosopher or linguist can now ignore metaphor’s upshot for epistemology and metaphysics.

Further, the authors are right in their claim that what insider cliques in analytic philosophy continue to consider prestigious work–piecemeal defining of truth conditions for abstract words as if they bore a literal rather than metaphorical pedigree–is bankrupt stuff. Lakoff and Johnson are the Lewis and Clark of philosophy’s Age of Metaphor, not always getting their positions right but endlessly clearing intellectual paths for others.

That said, the repercussions they announce for “reason” and the way they clash with Calne suggest why Philosophy in the Flesh, despite its girth, fails to settle the brute matter of what reason is. It should, for instance, give Lakoff and Johnson pause that while they claim “evidence from cognitive science shows that classical faculty psychology is wrong,” Calne finds considering reason a “faculty” perfectly adequate. That’s because he, the professional neurologist and amateur historian of ideas, unlike Lakoff and Johnson, the gushy devotees of cognitive science, never forgets that “reason” and its cognates are cultural terms whose delineation can never exceed in precision the official compromises of lexicographers.

Lakoff and Johnson, instead, believe that concepts such as reason “are neural structures” and that conceptual inference is simply “sensorimotor inference.” They thus accept materialist identification between words and concepts, on the one hand, and neurological matter, on the other. Far from being radically new, of course, that flirting with mind-body identity is as old as Plato’s Phaedo. And, contrary to what they claim, nothing in contemporary cognitive science or philosophy requires us to accept it.

None other than Steven Rose, a leading neuroscientist, reminds us in From Brains to Consciousness?: Essays on the New Sciences of the Mind (1998) that “being able to map mental processes into physiological, anatomical and biochemical mechanisms” may be able to tell us “how the brain/mind works,” but it “will not be able to tell us what the mind is doing and why. These questions will have to be answered at a higher level of analysis, and using a different language, than that offered by the best of neuroscientific technology.”

It’s clear, however, that Lakoff and Johnson see their work as analogous to the human genome project, with metaphorically soaked concepts ultimately to be neuronally coded and pinned. Unless, however, neurologists find name tags in the gray stuff, of the sort Mom sewed into your Camp Kitcheewawa T-shirts (“This sliver of cerebellum holds Bobby Smith’s conception of happiness”), the connections will depend on culturally driven associations. The authors should have spent more time with amateur etymologist Raymond Williams, whose entry on “Rational” in Keywords (1976) provides a judicious guide to the zigs and zags of reason and its oddball relatives (particularly “reasonable” and “rationalize”).

The authors might also have acknowledged that the straw-man philosophical tradition they persist in depicting as massively Cartesian and hostile to the body has been powerfully altered by pragmatism, Wittgenstein and deconstruction, so that many anti-a priori beliefs Lakoff and Johnson advance might be regarded as articulated by the others, minus the neuronal chemistry. (The authors do offer Dewey and Merleau-Ponty appreciative bows, but ignore their focus on the social construction of concepts.)

Calne, the neurologist, recognizes better than Lakoff and Johnson that it’s not “science” that decides where a concept begins and ends but culture, often after a spirited rhetorical battle. As a revisionist intellectual, he thus plunges ahead, seeking to tailor reason to his own wishes even as he blithely speaks of “reason’s nature.” Why does he believe reason can’t direct our goals?

Unlike emotions, reason does not entail needs that crave satisfaction. It is, furthermore, hard to imagine how reason would operate if it did crave satisfaction, for then it would not compete with emotions, it would be an emotion; we would feel reason in the way we feel anger (which craves a fight) or fear (which craves a flight). The separation of reason from motivation is fundamental to–even constitutive of–human cognition.

Despite Calne’s argument, scientific and philosophical juries remain out on whether to slice motivational aspects of thought away from reason and dump them in the “emotion” category. In this volatile intellectual arena, Calne can thus safely construe reason as a solely instrumental activity, just as Lakoff and Johnson can equate it to embodied metaphors. The point Calne, Lakoff and Johnson all play down in their eagerness to promote customized versions of reason is that it is ultimately public, deliberative lobbying and usage that determine what will count as “reason,” not neuronal reactions associated with individual judgments.

On that score, for all their industry, Lakoff and Johnson display little energy for considering how their vision violates deeply held views of metaphorical genius as an individual gift. They slight the creative side of metaphor, the ability of literary and scientific genius to reject clichéd associations and images. In their final chapter, Lakoff and Johnson assert that “we do not, for the most part, have control over how we conceptualize situations and reason about them,” and “we cannot freely change our conceptual systems by fiat.”

Tell it to Newton and Mallarmé, to Einstein and Yeats. Aristotle famously wrote that to be a master of metaphor is the greatest thing of all. Lakoff and Johnson describe our minds as products of metaphor. The truth, Aristotle would doubtless point out, is in between.

Finally, if the new reasoning about reason sometimes falters because it fails to square with previous wisdom we still support, it also loses a few revolutionary points for reiterating the previously better said. Does Calne truly take us far beyond Hume’s 1739 judgment that “reason is…the slave of the passions, and can never pretend to any other office than to serve and obey them”? Or Ovid’s observation that “what is now reason was formerly impulse”?

As for Lakoff and Johnson, we can similarly ask whether the tiresome social-science sedulousness with which they proceed renders their message vastly different from Roger Bacon’s thirteenth-century insight that “reasoning draws a conclusion–but does not make the conclusion certain, unless the mind discovers it by the path of experience.” And whether Wilde did not intuit the essence of Philosophy in the Flesh in having Lord Henry observe in The Picture of Dorian Gray, “I can stand brute force, but brute reason is quite unbearable…. It is hitting below the intellect.”

Philosophical revolutionaries resemble political ones in speaking too quickly for the rest of us. Science may solve various mysteries of neural causation, but it will be “culture” that decides how the numbers and chemistry hook up with the words and concepts we know and love. Stimulating as they are, these books offer reasons of which reason itself knows nothing.