The Blot

Ahti Veikko Pietarinen*, Francesco Bellucci, Angelina Bobrova, Nathan Haydon, Mohammad Shafiei

*Corresponding author for this work

Research output: Chapter in book/report/conference proceedingConference proceedingpeer-review

3 Citations (Scopus)


The blot is a sign in Peirce’s diagrammatic syntax of existential graphs that has hitherto been neglected in the literature on logical graphs. It is needed in order to trigger the cut-as-negation to come out from the scroll, namely from the implicational sign of a positive implicational (paradisiacal) logic. Since the cut-as-negation presupposes the blot and the scroll, what does the blot represent? On the one hand, it stands for constant absurdity, but on the other hand, Peirce takes it to be an affirmative sign. This paper explores the blot and its logical and conceptual properties from the multiple perspectives of notation, rules of transformation, icons, and scriptibility of graphs. It explains the apparent conflict in the blot’s meaning in its capacity of giving rise to the pseudo-graph that exploits positive character of absurdity. In effect, the blot is the mirror image of the sheet of assertion, not its complementation. On the sheet, it acts as a non-juxtaposable singularity.

Original languageEnglish
Title of host publicationDiagrammatic Representation and Inference
Subtitle of host publication11th International Conference, Diagrams 2020, Tallinn, Estonia, August 24–28, 2020, Proceedings
EditorsAhti-Veikko Pietarinen, Peter Chapman, Leonie Bosveld-de Smet, Valeria Giardino, James Corter, Sven Linker
PublisherSpringer Cham
Number of pages14
ISBN (Electronic)9783030542498
ISBN (Print)9783030542481
Publication statusPublished - 29 Jul 2020
Event11th International Conference on the Theory and Application of Diagrams, Diagrams 2020 - Tallinn, Estonia
Duration: 24 Aug 202028 Aug 2020

Publication series

NameLecture Notes in Computer Science
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349
NameLecture Notes in Artificial Intelligence
NameDiagrams: International Conference on Theory and Application of Diagrams


Conference11th International Conference on the Theory and Application of Diagrams, Diagrams 2020
Internet address

Scopus Subject Areas

  • Theoretical Computer Science
  • Computer Science(all)

User-Defined Keywords

  • Absurdity
  • Blot
  • Existential graphs
  • Pseudo-graph
  • Scriptibility
  • Scroll


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