oracle at delphi Archives

Why Self-Deception Belongs Within Critical Thinking

The priestess of Apollo at Delphi. Before seeking answers from the oracle, visitors first met with the words, ‘Know Thyself.’

Critical thinking has never been more popular. Schools, universities, and employers encourage us to evaluate evidence, identify logical fallacies, and recognise cognitive biases. Entire books are devoted to helping us think more clearly.

Yet intelligent people continue to believe ridiculous things.

They buy into political propaganda, dubious medical claims, financial scams, cults, conspiracy theories, and all manner of comforting or self-serving lies. They do so not because they lack intelligence, and often not because they lack evidence.

They do so because modern critical thinking shares our greatest blind spot. It teaches us how to analyse arguments, but not how to analyse ourselves.

Most books on critical thinking treat reasoning as though it were mathematics. Learn the rules and you will think more clearly. But reason is not merely an intellectual achievement. It is also a moral and psychological one. We do not merely need sharper minds, but greater courage and honesty.

The greatest obstacle to reason is neither dullness nor ignorance. It is our unconscious need to protect our sense of self. This is the realm of self-deception.

Unlike ordinary deception, self-deception is unconscious. We do not deliberately lie to ourselves. Instead, we unconsciously reshape reality to preserve a comforting image of who we are. We rationalise our failures, project our faults onto others, and convince ourselves that what we want to be true is true. These are not simply errors of reasoning but acts of self-protection.

This is why intelligent people can cling to implausible beliefs despite overwhelming evidence. Often, they are not defending an argument so much as defending themselves.

Cognitive biases explain how our thinking goes astray. Self-deception explains why.

To think clearly, then, it is not enough to study logic, rhetoric, and cognitive bias. We must also understand the unconscious forces that distort our judgement before reason has even had a chance to speak. Self-deception is not peripheral to critical thinking. It belongs at its very heart.

More than two thousand years ago, Socrates reached much the same conclusion. Rather than speculate about the natural world, he turned philosophy towards the study of ourselves.

In Plato’s Phaedrus, as they pass the place where Boreas is said to have carried off Orithyia, Phaedrus asks Socrates whether he believes the story. Socrates politely declines the invitation. While still ignorant of himself, he says, he has no interest in such questions:

I must first know myself, as the Delphian inscription says; to be curious about that which is not my concern, while I am still in ignorance of my own self, would be ridiculous.

For Socrates, self-knowledge came before all other enquiry.

Perhaps it should also come before critical thinking.

Socrates had been inspired by the oracle at Delphi, the greatest oracle of the ancient world. Long before there were textbooks on critical thinking, there was a two-word inscription above the Temple of Apollo at Delphi:

Γνῶθι σεαυτόν

Know thyself.