Reason as a Social Construct: The Self-Refuting Fallacy

Denying reason requires using reason: the fallacy that bites its own tail

Asevering that «reason is merely a social construct» presents, according to one participant, an inherent problem: the one making this claim is arguing. And arguing implies distinguishing truth from falsehood, preferring one thesis over its opposite, and appealing to coherence. This is the definition of self-refutation, or performative contradiction: the statement destroys itself upon being uttered, just like saying «I do not exist» while speaking.

What is performative contradiction

The analysis breaks down this mechanism into four movements: formulating an argument, separating truth from falsehood, maintaining that one's own thesis is preferable, and appealing to logic and evidence. The four movements require precisely what is being denied.
The conclusion is absolute: to deny reason, one must necessarily employ it.

From this arises the second line of attack. If reason were purely societal consensus, one would simply change the convention. Against this, it is argued that there exists a biological and cognitive basis—a brain that processes causal regularities, detects inconsistencies, and updates beliefs based on new information—which is a product of natural selection and nervous system development, not social agreement.

The relativist rebuttal: all perceptions are valid

The objection arrives from the other flank. All perception is biased; the belief system is influenced by personal history and cannot be entirely abandoned. In that reading, we are inhabitants of a conceptual prison where wars are fought and lives lost.
The proposed escape is not logical but spiritual: to let go of the conflict, relativize, and admit that the only truth is inner silence.

And this is where everything stalls. One side demands coherence to rebut; the other declares it a tool of the ego.
When disagreement concerns the very rules of the game, there is no common ground upon which to settle. Neither Schrödinger's cat, invoked by one participant against the Aristotelian principle of non-contradiction, nor Aristotle himself resolves it.