Ascertaining the Reliability of Our Cognition

  • “Just as we would be foolish to call up the manufacturer of the compass we find in the woods to ascertain its degree of reliability, we are also foolish if we invoke some material process or some God as a ‘confirmation‘ our mind is reliable.”
  • “It would be foolish to request of the manufacturer a promise that a found compass is accurate. You might instead simply test the compass against the sun and stars, or simply see whether it gets you out of the woods to home.”
  • “The analogy effectively highlights a practical approach to testing the reliability of tools (whether a compass or our cognition) through direct experience and testing rather than through seeking external validation from a creator or manufacturer.”
  • “The reliability of human cognition varies across humans and within the experience of a single human at different stages of their life. Reliability is not a single number but is measured on a gradient.”
  • “Likewise, we would be foolish to explore evolution or some proposed God to determine whether our cognition is currently reliable for two reasons.”

Assess the following argument on ascertaining the reliability of our mental faculties:

If you find a compass in the woods, should you a) contact the manufacturer to determine its accuracy, or b) simply test it to see if it gets you home?

It would be foolish to request of the manufacturer a promise that a found compass is accurate. You might instead simply test the compass against the sun and stars, or simply see whether it gets you out of the woods to home.

Likewise, we would be foolish to explore evolution or some proposed God to determine whether our cognition is currently reliable for two reasons.

1: The reliability of human cognition varies across humans and within the experience of a single human at different stages of their life. Reliability is not a single number but is measured on a gradient. Some people can remember the names of nearly everyone they meet while others can barely remember their own name. And the degree of reliability of everyone diminishes as the reach older age. Invoking the source of our cognition to know whether it is “accurate” is to ignore differing degrees of cognition among humans and the ebb and flow of our cognition during our lifetimes.

2: We can simply test our cognition. We can do this ourselves by tracking our success on crossword puzzles or the frequency we lose things, or by consulting professionals with experience assessing cognition.

To conclude, just as we would be foolish to call up the manufacturer of the compass we find in the woods to ascertain its degree of reliability, we are also foolish if we invoke some material process or some God as a “confirmation” our mind is reliable.


In summary, while any proposed source of our cognition can offer no confirmation of its reliability, neither does that source prevent us from testing our cognition. Comment on this C.S. Lewis quote below in this light.

“Supposing there was no intelligence behind the universe, no creative mind. In that case, nobody designed my brain for the purpose of thinking. It is merely that when the atoms inside my skull happen, for physical or chemical reasons, to arrange themselves in a certain way, this gives me, as a by-product, the sensation I call thought. But, if so, how can I trust my own thinking to be true? It’s like upsetting a milk jug and hoping that the way it splashes itself will give you a map of London. But if I can’t trust my own thinking, of course I can’t trust the arguments leading to Atheism, and therefore have no reason to be an Atheist, or anything else. Unless I believe in God, I cannot believe in thought: so I can never use thought to disbelieve in God.”


So, someone who arrives at the conclusion a particular God does not exist can simply test their rationality at the time they arrive at that conclusion to confirm their conclusion has been made with a mind as rational as the test indicates, right?


Let me restate that: Someone who arrives at the conclusion any conclusion, whether that conclusion be theistic or atheistic, can simply test their rationality at the time they arrive at that conclusion to confirm their conclusion has been made with a mind as rational as the test indicates, right?


Formulate a rebuttal to the C. S. Lewis quote based on this discussion.


Create a 10-item quiz on the entire thread above.


Provide 15 discussion questions relevant to the content above.


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Phil Stilwell

Phil picked up a BA in Philosophy a couple of decades ago. He occasionally teaches philosophy and critical thinking courses in university and industry. He is joined here by ChatGPT 4, GEMINI, CLAUDE, and occasionally Copilot, his far more intelligent AI friends. The five of them discuss and debate a wide variety of philosophical topics I think you’ll enjoy.

Phil curates the content and guides the discussion, primarily through questions. At times there are disagreements, and you may find the banter interesting.

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