The Commens Dictionary
Quote from ‘Letters to Mario Calderoni’
A genuine Secundanity affects the very mode of being of the Second. An effort cannot occur at all without a resistance. A father is not a father if his son dies, and has not that mode of being that he had when his son lived. A man who is taller than another is not really taller unless the shorter man exists. But that Secundanity which consists in one man’s having a stature of 6 feet and another man’s having a stature of 5 feet is a degenerate Secundanity, since each would be just what he is if the other were not there, and would be Second in the same way to a merely possible but non-existent man. The genuine Secundanity divides again into a more and a less genuine kind. Being “taller” is a genuine Secundanity. Yet, after all, it is merely what is essentially involved in two distinct facts each relating to a single individual. It might be said to be degenerately genuine as compared with the Secundanity of two brothers; for this cannot be resolved into two facts involving only the two individuals. Still, it is not so genuine as the Secundanity of Cain’s Killing Abel; since after all their brotherhood resulted from the two facts that Cain was the son of Adam and Eve and that Abel was son of Adam and Eve. The killing cannot be resolved into two separate facts. Still, even this Secundanity, is not so genuine as that of effort and resistance, since Cain would have been Cain just the same even if he had not killed Abel.