Peirce's Existential Graphs

摘要

This paper traces relationships among the notations of Charles Sanders Peirce, G. Spencer-Brown and Gottlob Frege. We discuss Peirce's sign of illation in relation to Spencer-Brown's mark and Frege's conceptual graphs. The last part of the paper begins a direct comparison of methods of introducing logical quantifiers, showing that Peirce's method is directly related to that for Frege via a graphical duality between nested circles and trees.