Criticism of Frege's Five Arguments against Psychologism in Logic

Document Type : Original Research

Authors

1 Department of Philosophy, Faculty of Literature and Humanities, University of Isfahan, Isfahan, Iran

2 Department of Ethics, Faculty of Theology and Islamic Studies, University of Qom, Qom, Iran

Abstract
Frege always sought to present logic as a normative science, belonging to a timeless and placeless realm, distinct from empirical sciences, particularly psychology, which is inherently descriptive. In most cases, he adopts an anti-psychologistic approach, and his arguments are not explicitly stated. In this article, five of Frege’s arguments against psychologism have been reconstructed by studying his original texts. Since understanding these arguments is impossible without considering his definition of number as the subject of arithmetic, it is first shown how, according to Frege, a number must be defined as an objective entity. It is then demonstrated that Frege substantiates his position by distinguishing between the psychological origins of a proposition and its justification and proof, considering the concept of number as impersonal, differentiating logical laws from empirical laws, distinguishing between “what is true” and “what is held to be true,” and showing that a correct understanding of equality is only possible by regarding the concept of number as objective. However, Frege’s critics argue that by eliminating criteria for understanding meaning and disregarding the criteria for correct usage among language users in a linguistic community, he has omitted a significant part of the meaning of logic and reasoning.

Keywords

Subjects

- Blanchette P (2012). Frege’s conception of logic. Oxford: Oxford University Press.
- Brandom R (1994). Making it explicit: Reasoning, representing, and discursive commitment. Cambridge: Harvard University Press.
- Burge T (1979). Individualism and the mental. Midwest Studies in Philosophy. 4(1):73-122.
- Deutsch H, Marshall O, Irvine AD (2024). Russell’s paradox. Stanford: The Stanford Encyclopedia of Philosophy.
- Dummett M (1981). Frege: Philosophy of language. Cambridge: Harvard University Press.
- Frege G (1892). On sense and reference. In: Beaney M. The Frege reader. Hoboken: Blackwell. p. 151-171.
- Frege G (1982). The basic laws of arithmetic: Exposition of the system. Berkeley: University Of California Press.
- Frege G (2017). Conceptual notation and related articles. Jaberi T, translator. Tehran: IRIP Press. [Persian]
- Frege G (2023). The foundations of arithmetic. Jaberi T, translator. Tehran: Ghoghnoos Press. [Persian]
- Frege G, Kluge EW (1972). Review of Dr. E. Husserl’s philosophy of arithmetic. Mind. 81(323):321-337.
- Heck RG (2012). Reading Frege’s grundgesetze. Oxford: Oxford University Press.
- Oaksford M, Chater N (2009) Précis of Bayesian rationality: The probabilistic approach to human reasoning. Behavioral and Brain Sciences. 32(1):69-84.
- Porta M (2015). The evolution of Frege’s critique of psychologism and the Brentano School. FILOSOFIA UNISINOS. 16(3):199-211.
- Safari A (2014). Nature of number in analytical philosophy of Frege. Philosophical Investigations. 7(13):69-101. [Persian]
- Smith R (2022). Aristotle’s logic. Stanford: The Stanford Encyclopedia of Philosophy.
- Wright C (1983). Frege’s conception of numbers as objects. Aberdeen: Aberdeen University Press.
- Zalta EN (2023). Frege’s theorem and foundations for arithmetic. Stanford: The Stanford Encyclopedia of Philosophy.
Volume 5, Issue 3 - Serial Number 19
Summer 2025
Summer 2025
Pages 401-416

  • Receive Date 02 June 2025
  • Accept Date 09 August 2025
  • Publish Date 09 September 2025