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Justified True Belief: Plato, Gettier, and Turing

Part of the Boston Studies in the Philosophy and History of Science book series (BSPS,volume 324)


We examine the relationship between the justified true belief (JTB) account of knowledge and Plato’s theory about it as expounded in the Theaetetus. Considering Socrates’ remarks in the Theaetetus brings us to some concerns raised by Turing and to Wittgenstein’s famous comment explanations come to an end somewhere. We present two simple technical results which bear on the question. Finally, we look at the pragmatic aspects of knowledge attributions. In an Appendix we say a few words about Indian epistemology and Gettier problems.

It is so difficult to find the beginning.

Or, better: it is difficult to begin at the beginning.

And not try to go further back.

On Certainty, Ludwig Wittgenstein

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  1. 1.

    Note that Turing is neutral between thinking about the computer as a person or as a machine and his mentalistic terminology is defensible.

  2. 2.

    Thanks to Melvin Fitting for telling us about this example.


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Thanks to Aranzazu San Gines for some of the references. Arthur Collins also made a useful suggestion.

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Correspondence to Rohit Parikh .

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Parikh, R., Renero, A. (2017). Justified True Belief: Plato, Gettier, and Turing. In: Floyd, J., Bokulich, A. (eds) Philosophical Explorations of the Legacy of Alan Turing. Boston Studies in the Philosophy and History of Science, vol 324. Springer, Cham.

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