Abstract
Lewis Carroll (1832–1898) published a system of logic in the symbolic tradition that developed in his time. Carroll’s readers may be puzzled by his system. On the one hand, it introduced innovations, such as his logic notation, his diagrams and his method of trees, that secure Carroll’s place on the path that shaped modern logic. On the other hand, Carroll maintained the existential import of universal affirmative Propositions, a feature that is rather characteristic of traditional logic. The object of this paper is to untangle this dilemma by exploring Carroll’s guidelines in the design of his logic, and in particular his theory of existential import. It will be argued that Carroll’s view reflected his belief in the social utility of symbolic logic.
Similar content being viewed by others
Notes
Carroll’s real name was ’Charles Lutwidge Dodgson’. Carroll signed with his real name most of his mathematical works but signed his logical writings with his literary pseudonym (see [50]). Consequently, we will refer to him as ‘Lewis Carroll’ in this paper.
This function of formal languages relates to logical systems which belong to the tradition of Calculus. Some logicians such as Charles S. Peirce, Gottlob Frege, Giuseppe Peano, Bertrand Russell, and others, designed languages rather to perform an analysis of logical inferences [11].
It must be said here that some symbolic logicians, such as Venn, shared to some extent Cook Wilson’s view on the artificiality of the problems they were addressing. This led some of them to dismiss the utility of the first logic machines which were designed around 1880 [36].
Note that symbol ‘\(\dag \)’ stands for ‘and’ and is placed between the Premises, while stands, roughly, for ‘imply’ and is placed between the Premises and the Conclusion. Also, an accent stands for negation; for instance, \(x'\) represents not-x.
An elegant online demonstrator designed by Mark R. Richards shows how to solve syllogistic problems with Carroll’s diagrams. It is found at: https://lewiscarrollresources.net/gameoflogic/.
Carroll apparently invented this method on 16 July 1894. That day, he noted in his journal developing and using successfully what he called the “Genealogical method” [81, p. 155].
Interestingly, when Carroll communicated his method of trees in 1896 to his colleague Cook Wilson, the latter revealed using “for years” a similar procedure. Cook Wilson named his technique the method of “hanging plants”, which roughly are inverted trees [27].
Carroll’s first paradox, commonly known as the Barbershop paradox, appeared in 1894 in the journal Mind [20]. It led to a large debate for over a decade among British logicians regarding the nature of hypotheticals [46]. For a discussion of this paradox, see [59]. Carroll’s second paradox, commonly known as the paradox of inference, appeared in 1895 in the same journal [21]. It did not get any responses in Carroll’s lifetime, but was widely commented by twentieth century logicians and philosophers. For a discussion, see [12, 53].
This view is already found in Carroll’s journal on 15 December 1884, when he reported being “Again in logical difficulties: it now seems inevitable to make “all x is y” assert existence of x.” [80, p. 156].
Carroll apparently tested this view in 1894, as shown by his journal entry of 19 June that year: “I have been testing the theory that the Copula in Logic does not assert the existence of the subject, but that “all x are y” only means “if any x exist, all of them are y.” It works out right with “Barbara” etc., but fails in “Darapti,” which, with this interpretation, gives no conclusion” [81, p. 151].
Some authors suggested that Carroll may have changed his theory of existential import in subsequent parts of Symbolic Logic, which he never managed to complete [2, 9]. It is true that Carroll added to the section on existential import in the fourth edition of his treatise an opening note stating: “Note that the rules, here laid down, are arbitrary, and only apply to Part I of my “Symbolic Logic.”’ [22, p. 19]. However, it is unknown what change he may have made in subsequent parts.
It must be explained that this abridged notation rather expresses the conjunction of “Some x exist” and “No x are not-y”. Carroll simply noted that it was not necessary to explicitly mark the superfluous information contained in the Proposition “Some x are y”. The fact that “Some x exist” suffices for the purpose. Indeed, given that “Some x exist” and knowing that “No x are not-y”, it necessarily follows that “Some x are y” [22, p. 72] (see [32, pp. 40–41]).
References
Abeles, F.F.: Lewis Carroll’s method of trees: its origin in Studies in logic. Mod. Log. 1(1), 25–35 (1990)
Abeles, F.F.: Lewis Carroll’s formal logic. Hist. Philos. Logic 26(1), 33–46 (2005)
Abeles, F.F.: Lewis Carroll’s visual logic. Hist. Philos. Log. 28(1), 1–17 (2007)
Abeles, F.F. (ed.): The Logic Pamphlets of Charles Lutwidge Dodgson and Related Pieces. Lewis Carroll Society of North America, New York (2010)
Abeles, F.F.: Toward a visual proof system: Lewis Carroll’s method of trees. Log. Universalis 6, 521–534 (2012)
Abeles, F.F.: Mathematical legacy. In: Wilson, R., Moktefi, A. (eds) The Mathematical World of Charles L. Dodgson (Lewis Carroll) (pp. 177–215). Oxford University Press, Oxford (2019)
Abeles, F.F., Moktefi, A.: Hugh MacColl and Lewis Carroll: crosscurrents in geometry and logic. Philos. Sci. 15(1), 55–76 (2011)
Bannier, A., Bodin, N.: A new drawing for simple Venn diagrams based on algebraic construction. J. Comput. Geom. 8(1), 153–173 (2017)
Bartley, W.W., III. (ed.): Lewis Carroll’s Symbolic Logic. Clarkson N. Potter, New York (1986)
Beisecker, D.: Peirce and proof: a view from the trees. In: Chapman, P. et al. (eds.) Diagrammatic Representation and Inference (pp. 537–548), Birkhaüser, Basel (2018)
Bellucci, F., Moktefi, A., Pietarinen, A.-V.: Simplex sigillum veri: Peano, Frege and Peirce on the primitives of logic. Hist. Philos. Log. 39(1), 80–95 (2018)
Besson, C.: Norms, reasons, and reasoning: a guide through Lewis Carroll’s regress argument. In: Star, D. (ed.) The Oxford Handbook of Reasons and Normativity (pp. 504–528), Oxford University Press, Oxford (2018)
Bhattacharjee, R., Moktefi, A.: Revisiting Peirce’s rules of transformation for Euler–Venn diagrams. In: Basu, A., et al. (eds.) Diagrammatic Representation and Inference (in print). Springer, Cham (2021)
Bhattacharjee, R., Moktefi, A., Pietarinen, A.-V.: The representation of negative terms with Euler diagrams. In: Béziau, J.-Y., et al. (eds.) Logic in Question (in print). Birkhaüser, Basel (2021)
Boole, G.: An Investigation of the Laws of Thought. Macmillan, London (1854)
Braithwaite, R.B.: Lewis Carroll as logician. Math. Gazette 16(219), 174–178 (1932)
Burris, S., Legris, J.: The algebra of logic tradition. In: Zalta, E. N. (ed.) The Stanford Encyclopedia of Philosophy, at: https://plato.stanford.edu/archives/spr2021/entries/algebra-logic-tradition/ (2021)
Burton, J., Howse, J.: The semiotics of spider diagrams. Log. Universalis 11, 177–204 (2017)
Carroll, L.: The Game of Logic. Macmillan, London (1887)
Carroll, L.: A logical paradox. Mind 3(11), 436–438 (1894)
Carroll, L.: What the Tortoise said to Achilles. Mind 4(14), 278–280 (1895)
Carroll, L.: Symbolic logic: Part I, 4th edition. Macmillan, London (1897)
Carroll, L.: Letter to Louisa Dodgson, 21 March. The Berol Collection of Lewis Carroll, Fales Library, New York University, 1A/2/119 (1897)
Carroll, L.: Three Letters on Anti-Vaccination. The Lewis Carroll Society, London (1976)
Church, A.: Review of Lewis Carroll’s symbolic logic and the game of logic. J. Symb. Log. 25(3), 264–265 (1960)
Cohen, M.N., Gandolfo, A. (eds.): Lewis Carroll and the House of Macmillan. Cambridge University Press, Cambridge (1987)
Cook Wilson, J.: Letter to Charles L. Dodgson, 3 November. The John Cook Wilson Papers, Bodleian library, University of Oxford (1896)
Cook Wilson, J.: Statement and Inference. Clarendon Press, Oxford (1926)
Dunning, D.: The logician in the archive: John Venn’s diagrams and Victorian historical thinking. J. Hist. Ideas 82(4), in print (2021)
Durand-Richard, M.-J., Moktefi, A.: Algèbre et logique symboliques : arbitraire du signe et langage formel. In : Béziau, J.-Y. (ed.) La Pointure du Symbole (pp. 295–328). Pétra, Paris (2014)
Edwards, A.W.F.: Cogwheels of the Mind: The Story of Venn Diagrams. The Johns Hopkins University Press, Baltimore (2004)
Englebretsen, G.: Lewis Carroll on logical quantity. Jabberwocky 12(2), 39–41 (1983)
Englebretsen, G.: Something to Reckon with: The Logic of Terms. University of Ottawa Press, Ottawa (1996)
Englebretsen, G.: Carrollian Notes. College Publications, London (2021)
Englebretsen, G., Gilday, N.: Lewis Carroll and the logic of negation. Jabberwocky 5(2), 42–45 (1976)
Gardner, M.: Logic Machines and Diagrams. Harvester Press, Brighton (1983)
Geach, P.T.: Review of W. W. Bartley III’s Lewis Carroll’s Symbolic Logic. Philosophy 53, 123–125 (1978)
Green, J.: The problem of elimination in the algebra of logic. In: Drucker, T. (ed.) Perspectives on the History of Mathematical Logic (pp. 1–9), Birkhauser, Boston (1991)
Keynes, J.N.: Studies and Exercises in Formal Logic, 4th edition. Macmillan, London (1906)
Ladd-Franklin, C.: On the algebra of logic. In: Peirce, C. S. (ed) Studies in Logic (pp. 17–71). Little, Brown, and Company, Boston (1883)
Land, J.P.N.: Brentano’s logical innovations. Mind 1(2), 289–292 (1876)
Lindemann, J.L.: O jogo da lógica de Lewis Carroll: uma alternativa para o ensino médio. Refilo - Revista Digital de Ensino de Filosofia 3(2), 165–179 (2017)
MacColl, H.: Review of Lewis Carroll’s symbolic logic. Athenaeum 3599, 520–521 (1896)
Macula, A.J.: Lewis Carroll and the enumeration of minimal covers. Math. Mag. 68(4) (1995)
Marion, M., Moktefi, A.: La logique symbolique en débat à Oxford à la fin du XIXe siècle: les disputes logiques de Lewis Carroll et John Cook Wilson. Revue d’Histoire des Sci. 67(2), 185–205 (2014)
Moktefi, A.: Lewis Carroll and the British nineteenth-century logicians on the barber shop problem. Proc. Can Soc. Hist. Philos. Math. 20, 189–199 (2007)
Moktefi, A.: Beyond syllogisms: Carroll’s (marked) quadriliteral diagram. In: Moktefi, A., Shin, S.-J. (eds.) Visual Reasoning with Diagrams (pp. 55–72). Birkhäuser, Basel (2013)
Moktefi, A.: On the social utility of symbolic logic: Lewis Carroll against the Logicians. Studia Metodologiczne 35, 133–150 (2015)
Moktefi, A.: Are other people’s books difficult to read? The logic books in Lewis Carroll’s private library. Acta Baltica Historiae et Philos. Sci. 5(1), 28–49 (2017)
Moktefi, A.: Is it disgraceful to present a book of mathematics to a Queen? Math. Intell. 41(1), 42–50 (2019)
Moktefi, A.: Logic. In: Wilson, R. J., Moktefi, A. (eds.) The Mathematical World of Charles L. Dodgson (Lewis Carroll) (pp. 87–119). Oxford University Press, Oxford (2019)
Moktefi, A.: The Social shaping of modern logic. In: Gabbay, D., et al. (eds) Natural Arguments: A Tribute to John Woods (pp. 503–520). College Publications, London (2019)
Moktefi, A., Abeles, F.F.: The making of ‘What the Tortoise said to Achilles’: Lewis Carroll’s logical investigations toward a workable theory of hypotheticals. Carrollian 28, 14–47 (2016)
Moktefi, A., Bellucci, F., and Pietarinen, A.-V.: Continuity, connectivity and regularity in spatial diagrams for N terms. In: Burton, J., Choudhury, L. (eds.) DLAC 2013: Diagrams, Logic and Cognition (pp. 31–35), CEUR Workshop Proceedings 1132 (2014)
Moktefi, A., Bhattacharjee, R.: What are rules for? A Carroll-Peirce comparison. In: Basu, A., et al. (eds.) Diagrammatic Representation and Inference (in print). Springer, Cham (2021)
Moktefi, A., Edwards, A.W.F.: One more class: Martin Gardner and logic diagrams. In: Burstein, M. (ed.) A Bouquet for the Gardener (pp. 160–174). The Lewis Carroll Society of North America, New York (2011)
Montoito, R.: Lógica e Nonsense nas Obras de Lewis Carroll. Editora IFSul, Pelotas (2019)
Moretti, A.: Was Lewis Carroll an amazing oppositional geometer? Hist. Philos. Log. 35(4), 383–409 (2014)
Moser, V.: The problem of the barber-shop paradox by Lewis Carroll: a clash between intuition and rational thinking. Meta 6, 24–34 (2020)
Okashah, L.A.: Lewis Carroll’s contributions to artificial intelligence. Comput. Ind. Eng. 23(1–4) (1992)
Quine, W.V.: The algebra of attributes. Times Literary Suppl. 3937, 1018–1019 (1977)
Richards, M.: Mathematicians and their Gods. In: Lawrence, S., McCartney, M. (eds.) Charles Dodgson’s work for God, pp. 191–211. Oxford University Press, Oxford (2015)
Rosenhouse, J.: Games for Your Mind: The History and Future of Logic Puzzles. Princeton University Press, Princeton (2020)
Russell, B.: A Fresh Look at Empiricism. Routledge, London and New York (1996)
Russinoff, I.S.: The syllogism’s final solution. Bull. Symb. Log. 5(4), 451–469 (1999)
Sautter, F.T.: A bunch of diagrammatic methods for syllogistic. Log. Univ. 13, 21–36 (2019)
Savenije, B.: De Logische Wereld van Lewis Carroll en wat Alice daar Aantrof. Lewis Carroll Genootschap (2021)
Schumann, A., Adamatzky, A.: Physarum Polycephalum diagrams for syllogistic systems. IFColog J. Log. Appl. 2(1), 35–68 (2015)
Segerberg, K.: A Carrollian Introduction to Categorical Logic. Uppsala University, Uppsala (2000)
Senturk, I., Gursoy, N.K., Oner, T., Gursoy, A.: A novel algorithmic construction for deductions of categorical polysyllogisms by Carroll’s diagrams. Inf. Sci., in press (2021)
Shearman, A.T.: The Development of Symbolic Logic. Williams and Norgate, London (1906)
Shin, S.-J.: The Logical Status of Diagrams. Cambridge University Press, New York (1994)
Sidgwick, A.: Review of Lewis Carroll’s the game of logic. Nature 36(914), 3–4 (1887)
Simons, P.: Tree proofs for syllogistic. Stud. Log. 48(4) (1989)
Simons, P.: The Cambridge Companion to Brentano. In: Jacquette, D. (ed.) Judging Correctly: Brentano and the Reform of Elementary Logic, pp. 45–65. Cambridge University Press, Cambridge (2004)
Van Evra, J.: The development of logic as reflected in the fate of the syllogism 1600–1900. Hist. Philos. Log. 21, 115–134 (2000)
Venn, J.: The game of logic. Nature 36(916), 53–54 (1887)
Venn, J.: Symbolic Logic, 2nd edition. Macmillan, London (1894)
Wakeling, E.: The Logic of Lewis Carroll. Privately published (1978)
Wakeling, E. (ed.): Lewis Carroll’s Diaries, vol. 8. The Lewis Carroll Society, Clifford, Herefordshire (2004)
Wakeling, E. (ed.): Lewis Carroll’s Diaries, vol. 9. The Lewis Carroll Society, Clifford, Herefordshire (2005)
Acknowledgements
Earlier versions of this paper were partly presented at several events over the years, notably at the ‘History of Logic Meeting’ organized by the British Society for the History of Mathematics in Honour of Ivor Grattan-Guinness (London, 27 May 2017). The preparation of this paper benefited from the support of the TalTech internal grant SSGF21021.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Moktefi, A. Why Make Things Simple When You Can Make Them Complicated? An Appreciation of Lewis Carroll’s Symbolic Logic. Log. Univers. 15, 359–379 (2021). https://doi.org/10.1007/s11787-021-00286-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11787-021-00286-1