A logical

graph Graph may refer to: Mathematics *Graph (discrete mathematics), a structure made of vertices and edges **Graph theory, the study of such graphs and their properties *Graph (topology), a topological space resembling a graph in the sense of discre ...

is a special type of diagrammatic structure in any one of several systems of graphical

syntax In linguistics, syntax () is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure ( constituency) ...

that

Charles Sanders Peirce Charles Sanders Peirce ( ; September 10, 1839 – April 19, 1914) was an American philosopher, logician, mathematician and scientist who is sometimes known as "the father of pragmatism". Educated as a chemist and employed as a scientist for t ...

developed for

logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premises ...

. In his papers on ''

qualitative logic An entitative graph is an element of the diagrammatic syntax for logic that Charles Sanders Peirce developed under the name of qualitative logic beginning in the 1880s, taking the coverage of the formalism only as far as the propositional or ...

'', ''

entitative graph An entitative graph is an element of the diagrammatic syntax for logic that Charles Sanders Peirce developed under the name of qualitative logic beginning in the 1880s, taking the coverage of the formalism only as far as the propositional or ...

s'', and ''

existential graph An existential graph is a type of diagrammatic or visual notation for logical expressions, proposed by Charles Sanders Peirce, who wrote on logical graph, graphical logic as early as 1882,Peirce, C. S., " n Junctures and Fractures in Logic (ed ...

s'', Peirce developed several versions of a graphical

formalism Formalism may refer to: * Form (disambiguation) * Formal (disambiguation) * Legal formalism, legal positivist view that the substantive justice of a law is a question for the legislature rather than the judiciary * Formalism (linguistics) * Scient ...

, or a graph-theoretic

formal language In logic, mathematics, computer science, and linguistics, a formal language consists of words whose letters are taken from an alphabet and are well-formed according to a specific set of rules. The alphabet of a formal language consists of symb ...

, designed to be interpreted for logic. In the century since Peirce initiated this line of development, a variety of formal systems have branched out from what is abstractly the same formal base of graph-theoretic structures.

External links

{{commonscat-inline, Logical graphs
Logical Graph

Existential Graphs
Jay Zeman, ed., U. of Florida. With 4 works by Peirce.
Frithjof Dau's page of readings and links on existential graphs
includes lists of: books exclusively on existential graphs; books containing existential graphs; articles; and some links and downloadables.

Xin-Wen Liu, Institute of Philosophy, Chinese Academy of Social Sciences, Beijing, PRC. A whole lot there. Mathematical logic Charles Sanders Peirce Diagrams

See also

External links