 Peirce created a novel and productive analogy in representation between chemistry and the logic of relation by adopting the doctrine of valency as the key element for the analogy, as shown in the above two diagrams. Believing that this graphic style of representation would help us conceive the consequences or effects of a given relation in a more efficient  way,[26]  Peirce presents Entitative Graphs, which is a predecessor of  EG.[27]