Bibliography

On the Foundations of Mathematics

An argument whose intended or professed interpretant is not really an interpretant of it […] is a fallacy.

A proposition [whose] professed or intended object is not really its object is false.

Even an ‘icon,’ if it is going to be a sign, at all, must be related to an object of which it is the sign. But what makes it suitable to be a sign is that it possesses certain qualities. Those qualities it would possess just the same though the object did not exist.

Every sign functioning as such determines an interpretant sign. Generally there are [many] different signs of different meaning which the sign authorizes. I call all these its interpretants. The complete interpretant is the sign itself.

Every sign is regarded as having an object, or real thing to which it corresponds. But though regarded as having an object, it does not cease to be a sign because no such object really exists.

A sign which separately specifies what object is represents is a proposition; and a mere icon cannot do this. An index may; as a weather-cock does.

A quality is whatever it is in itself. It has such mode of being as it has independently of any other quality, of existing in any subject, and of being represented.