Rudolf Carnap (1935) Philosophy and Logical Syntax. p. 9-10
Great Books: The Foundation of a Liberal Education (1954)
2000s, The Logic of the Colorblind Constitution (2004)
Source: Meaning And Necessity (1947), p. 7-8 as cited in: Erich Reck (2011) " Carnapian Explication: A Case Study and Critique http://www.faculty.ucr.edu/~reck/Reck-C'ian%20Explic.%20(3rd.%20rev.).pdf"
Language as Conspiracy, p. 277
Everything Is Under Control (1998)
Context: You need the "is of identity" to describe conspiracy theories. Korzybski would say that proves that illusions, delusions, and "mental" illnesses require the "is" to perpetuate them. (He often said, "Isness is an illness.")
Korzybski also popularized the idea that most sentences, especially the sentences that people quarrel over or even go to war over, do not rank as propositions in the logical sense, but belong to the category that Bertrand Russell called propositional functions. They do not have one meaning, as a proposition in logic should have; they have several meanings, like an algebraic function.
Language in Thought and Action, p. 271, (1939), S.I. Hayakawa
Anatol Rapoport. " Various meanings of “theory”." http://www.acsu.buffalo.edu/~fczagare/PSC%20504/Rapoport%20(1958).pdf American Political Science Review 52.04 (1958): 972-988.
1950s
Recent Work on the Principles of Mathematics, published in International Monthly, Vol. 4 (1901), later published as "Mathematics and the Metaphysicians" in Mysticism and Logic and Other Essays (1917)
1900s
Context: Pure mathematics consists entirely of assertions to the effect that, if such and such a proposition is true of anything, then such and such another proposition is true of that thing. It is essential not to discuss whether the first proposition is really true, and not to mention what the anything is, of which it is supposed to be true. Both these points would belong to applied mathematics. We start, in pure mathematics, from certain rules of inference, by which we can infer that if one proposition is true, then so is some other proposition. These rules of inference constitute the major part of the principles of formal logic. We then take any hypothesis that seems amusing, and deduce its consequences. If our hypothesis is about anything, and not about some one or more particular things, then our deductions constitute mathematics. Thus mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true. People who have been puzzled by the beginnings of mathematics will, I hope, find comfort in this definition, and will probably agree that it is accurate.
The Foundations of Mathematics (1925)
