As material things always come with non-being, so too analogous terms always come with negation. A blind man reasoning about colors describes both ignorance, and a knowledge by analogy. The difference is whether we take the blind man insofar as he has no proper knowledge (ignorance) or whether we take him as understanding colors in a way that does not require proper knowledge of the thing spoken of, as happens for example in modern science when it understands colors analogously as certain frequencies of waves.