 While Peirce mainly presented linear expressions in his official writings from 1870 to  1885,[22]  the notation adopted in Frege’s 1879 Begriffsschrift is more iconic; it is at least not as linear as Peirce’s in the above period. However, it is Peirce, not Frege, who invented a full-blown non-symbolic system for first-order logic—Existential Graphs. It is Peirce’s EG, not his linear first-order notation, which is presented as a deductive system with inference rules. As the EG system has been investigated more rigorously, philosophical questions involving Peirce’s invention of the system have been raised as well. The discovery of EG’s power and novelty has naturally led us to other parts of Peirce’s philosophy. Why and how did the invention of EG come about? What does EG reveal about Peirce’s view of logic and representation?