It seems a strange thing, when one comes to ponder over it, that a sign should leave its interpreter to supply a part of its meaning; but the explanation of the phenomenon lies in the fact that the entire universe—not merely the universe of existents, but all that wider universe, embracing the universe of existents as a part, the universe which we are all accustomed to refer to as ‘‘the truth’’— that all this universe is perfused with signs, if it is not composed exclusively of signs.

—Charles Sanders Peirce