A purple cow is a confirming instance of the hypothesis that all crows are black.
Hempel's Paradox
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References
Carnap, R. Logical Foundations of Probability. Chicago, IL: University of Chicago Press, pp. 224 and 469, 1950.Erickson, G. W. and Fossa, J. A. Dictionary of Paradox. Lanham, MD: University Press of America, pp. 79-81, 1998.Gardner, M. Hexaflexagons and Other Mathematical Diversions: The First Scientific American Book of Puzzles and Games. New York: Simon and Schuster, pp. 52-54, 1959.Goodman, N. Ch. 3 in Fact, Fiction, and Forecast. Cambridge, MA: Harvard University Press, 1955.Hempel, C. G. "A Purely Syntactical Definition of Confirmation." J. Symb. Logic 8, 122-143, 1943.Hempel, C. G. "Studies in Logic and Confirmation." Mind 54, 1-26, 1945.Hempel, C. G. "Studies in Logic and Confirmation. II." Mind 54, 97-121, 1945.Hempel, C. G. "A Note on the Paradoxes of Confirmation." Mind 55, 1946.Hosiasson-Lindenbaum, J. "On Confirmation." J. Symb. Logic 5, 133-148, 1940.Whiteley, C. H. "Hempel's Paradoxes of Confirmation." Mind 55, 156-158, 1945.Referenced on Wolfram|Alpha
Hempel's ParadoxCite this as:
Weisstein, Eric W. "Hempel's Paradox." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/HempelsParadox.html