A good example of a
vague concept is the concept of a heap of sand -- two or three grains of sand is not a heap, but a thousand is. So how many grains of sand does it take to make a heap? There is no clear line. It appears to be
paradoxical to ask at what point a heap stops being a heap as grains are removed. This is known as the
paradox of the heap or the
sorites paradox (from the
Greek language word for "heap").
See also: