Reason Without Roots: What the Enlightenment's Crisis Reveals About Itself

The experiment in the dark room

In Joseph Wright of Derby's An Experiment on a Bird in the Air Pump (1768), a white cockatoo is dying in a glass vessel while the natural philosopher works the pump and the family watches. Some faces show wonder. One child buries her face against her father's coat. Wright painted the scene in near-total darkness, illuminated only by a candle the experimenter holds between himself and the bird.

Eliane Glaser opens her essay 'Flickering Enlightenment' with this painting, and the choice is apt. The Enlightenment's defining self-image is light — the Aufklärung, the lumières, the illuminismo — yet Wright catches the moment when that light depends entirely on the experimenter's hand. Blow out the candle and the bird dies in darkness. Glaser's argument is that the Enlightenment's critics, from the postmodern Left to the nationalist Right, have been grabbing at the candle. Her aim is to rescue reason from its would-be defenders as much as from its attackers.

What Glaser gets right

Glaser's central complaint is that Enlightenment reason has been caricatured twice over: first by postmodern critics who collapsed it into a cover story for colonial power, and then by reactionary populists who blamed it for 'globalist' rootlessness. Both attacks pick off a distorted target. The actual Enlightenment was plural, contested, and frequently self-critical. Voltaire was not Condorcet. Hume was not d'Holbach.

She is also right that the retreat from reason has concrete casualties. When public health authorities lost credibility during the pandemic, people died of preventable diseases because the institutional infrastructure of expert testimony had been hollowed out by decades of epistemological relativism. When courts defer to the loudest voice rather than the best-attested argument, the poor and the vulnerable lose first. Glaser names these costs, and naming them is necessary.

Where the argument stalls

Yet 'Flickering Enlightenment' reaches a point at which the defense of reason cannot quite close. Glaser wants to hold that reason is valuable, that it is under threat, and that it must be defended — but she is working within a tradition that has made it philosophically awkward to say why reason is binding. If values are ultimately matters of preference, if there is no normative order antecedent to human construction, then the defense of reason is just one preference contending against others. The candle flickers because the wick has been cut.

The Enlightenment's dominant epistemological moves — the rejection of final causes, the confinement of metaphysics, the reduction of the good to the useful or the agreed-upon — were precisely the moves that made reason harder to ground. Kant saw part of the problem and tried to solve it by grounding rationality in the structure of the subject. But a reason that derives its authority entirely from the subject's own legislation has difficulty explaining why any particular subject should submit to it.

Maritain put the structural issue plainly: reason is not a system, an artefactum; it is a spiritual organism.[^5] Reason is not a tool the human person invented and can revise at will. It is an expression of what the person already is — a being constituted by a prior act of existing that is not of the person's own making.

Actus essendi and the grounding problem

For Aquinas, the intellect's capacity to know being is not a contingent feature of one cultural moment. It follows from the kind of thing a human person is: a composite of act and potency whose intellective power is ordered to being as such. The act of existing — the actus essendi — is prior to any particular essence and is what makes the intellect's openness to reality possible at all. Norris Clarke read this as a corrective to contemporary philosophy's tendency to treat existence as merely the blank fact that something happens to be here.[^1]

Corneliu Fabro developed the same point through the doctrine of participation. To say that creatures participate in being is to say that their act of existing is received — they do not generate their own intelligibility from within.[^2] If human knowing were purely self-contained, it would be a mirror looking at itself. Participation is what opens the mirror outward.

Glaser cannot make this move because it requires affirming that being has a structure antecedent to and normative for human reason — a structure that is not the product of social negotiation. Once the Enlightenment severed reason from its metaphysical grounding, the only available defenses became pragmatic (reason works better than the alternatives) or procedural (reason is what we have agreed to call the method by which disputes are settled). Both are vulnerable to the same objection: they presuppose what they need to prove. Pragmatic defenses invite the question, works for whom, toward what end? Procedural defenses invite the question, who agreed, and why should the agreement bind me?

A contemporary Thomistic account helps clarify what is at stake. The capacity to know beings through their forms depends on the intellect's being genuinely ordered to a reality it does not produce.[^3] What Enlightenment epistemology struggled to accommodate was precisely this: the idea that the world is already structured in a way the mind can follow, not because the mind projected that structure onto chaotic matter, but because both mind and world derive their intelligibility from the same source. In Ferdinand Ulrich's terms, the intellect cut off from the act of being that sustains it begins to treat its own operations as self-sufficient.[^4] When reason forgets that it receives its light rather than generating it, it becomes susceptible to the very instrumentalization Glaser fears: harnessed to power, bent to ideology, reduced to calculation.

What a grounded defense looks like

None of this means the Enlightenment's practical achievements are forfeit. The development of experimental method, the articulation of legal rights, the expansion of literacy and public argument — these are real goods, and the Catholic intellectual tradition has never argued otherwise. What it argues is that these goods cannot sustain themselves on the philosophical foundations the Enlightenment typically offered for them.

Human dignity is a claim the Enlightenment wanted to make universal. Kantian dignity is rationally rigorous but depends on a metaphysics of the rational subject that Kant himself could not fully defend. Utilitarian dignity tends to evaporate whenever the calculus runs the other direction. Maritain's counter-proposal — that dignity follows from the person's existence as an image of God, prior to any social recognition — is less modest but more stable.[^5]

Glaser's essay ends with an appeal to renew Enlightenment institutions. Courts, universities, a free press, scientific journals — these are worth defending. But the defense will not hold if it rests only on the claim that these institutions have worked reasonably well so far. They worked because they inherited, and for a long time lived off the capital of, a deeper account of human knowing and human worth. That account did not originate in the eighteenth century. It was already there in Aquinas, preserved and developed through a tradition the Enlightenment partly rejected and partly forgot.

The cockatoo in Wright's painting survived some sessions; the experimenter could let the air back in. The question Glaser's essay presses, without quite answering, is whether reason can breathe again once the metaphysical air has been pumped out.

Footnotes

[^1]: Norris Clarke, 'The Integration of Person' — on the Thomistic actus essendi as a corrective to the contemporary sense of existence as brute presence.

[^2]: Mitchell, Vol. 2, 'Being and Participation in Cornelio Fabro.'

[^3]: Michael Gorman, A Contemporary Introduction to Thomistic Metaphysics.

[^4]: Ferdinand Ulrich, Homo Abyssus — 'the intellect, cut off from the act of being, treats its own operations as self-sufficient.'

[^5]: Jacques Maritain, The Degrees of Knowledge — 'it is not a system, an artefactum, it is a spiritual organism.'

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