Continuum Fallacy

Rooted in the sorites paradox (from the Greek soros, "heap"), first attributed to the 4th-century BC Megarian philosopher Eubulides of Miletus. His original puzzle asked when removing grains one by one causes a heap of sand to stop being a heap. The nickname "fallacy of the beard" applies the same logic to facial hair — at what point does stubble become a beard? The problem of drawing sharp lines across continuous spectra has occupied logicians for over two millennia.