"The theory of negation must be redone with reference to the phenomena of relevance..."
You will hardly have found time to read my French article. Koyré wrote from Paris that he has passed the article on to the Comité, and he raised an objection: Koyré claims that the sentence "The sum of the angles in a triangle is not equal to the color red" is a true sentence. This objection has made me very agitated, since on the basis of the concepts of truth which are accepted in contemporary logic it is completely justified. In my article I had called the sentence "The sum of the angles in a triangle is equal to the color red" meaningless [sinnlos], since there is no relation of relevance between the terms. After receiving the letter from Koyré I walked the streets of Cambridge for two hours and made the discovery that K.'s sentence is true in the sense that there is no relation of relevance between "red" and the sum of the angles. K.'s sentence is thus true in a completely different sense from, e.g., the following sentences: 1) "2 + 3 is not equal to 7"; 2) "Portugal is not on the Black Sea." In other words, the theory of negation has to be completely redone with reference to the phenomena of relevance, and the concept of truth must be refined in the same orientation. There is a paragraph on relevance and logic in my book. The French essay grew out of this paragraph. I shall resist the truly powerful temptation to rewrite this entire paragraph or to draw conclusions from it with respect to negation and truth. You can well imagine that I am very excited; for at least to some extent the validity of my theory of relevance depends on what is to be found in this newly-opened-up horizon. If only I weren't so isolated here!
Letter from Aron Gurwitsch to Alfred Schutz, December 17, 1950. Found in Philosophers in Exile















