Volume 5, Issue 2 (2025)
jpt 2025, 5(2): 141-154 |
Back to browse issues page
Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
Nabati F. The Importance of Paying Attention to the Logica Docens/Logica Utens Duality. jpt 2025; 5 (2) :141-154
URL: http://jpt.modares.ac.ir/article-34-79604-en.html
URL: http://jpt.modares.ac.ir/article-34-79604-en.html
Department of Philosophy, Faculty of Persian Literature and Foreign Languages, Allameh Tabataba'i University, Tehran, Iran
Full-Text [PDF 634 kb]
(242 Downloads)
| Abstract (HTML) (1023 Views)
Full-Text: (11 Views)
Introduction
From the beginning of Muslim logicians' and philosophers' acquaintance with Aristotelian logic, the question has always been raised: Is logic a science, or is it merely a tool for other sciences? And if it is a science, does it belong to theoretical sciences, or should it be considered among practical sciences? Christian medieval logicians, influenced by the logical tradition of Muslims, engaged with the discussions raised among Muslim logicians and entered into the debate about the status and scientific position of logic. It was in this context that the well-known dichotomy of logica docens and logica utens was born. Thomas Aquinas was the first to use this dichotomy. After him, other medieval logicians, such as Buridan and Duns Scotus, frequently employed this distinction [Lu-Adler, 2018: 51]. After the Renaissance, this dichotomy and its related concepts, like many other significant logical discussions, were largely forgotten. However, Charles Sanders Peirce revived attention to this dichotomy in the late 19th century and used it to explain and clarify certain logical issues.
From the beginning of Muslim logicians' and philosophers' acquaintance with Aristotelian logic, the question has always been raised: Is logic a science, or is it merely a tool for other sciences? And if it is a science, does it belong to theoretical sciences, or should it be considered among practical sciences? Christian medieval logicians, influenced by the logical tradition of Muslims, engaged with the discussions raised among Muslim logicians and entered into the debate about the status and scientific position of logic. It was in this context that the well-known dichotomy of logica docens and logica utens was born. Thomas Aquinas was the first to use this dichotomy. After him, other medieval logicians, such as Buridan and Duns Scotus, frequently employed this distinction [Lu-Adler, 2018: 51]. After the Renaissance, this dichotomy and its related concepts, like many other significant logical discussions, were largely forgotten. However, Charles Sanders Peirce revived attention to this dichotomy in the late 19th century and used it to explain and clarify certain logical issues.
In this paper, I aim to demonstrate that focusing on this dichotomy can be beneficial in addressing certain logical issues. Peirce, as the reviver of this dichotomy, has referred to many of these topics.
Applications of the Logica Docens/Logica Utens Dichotomy
Critique of Logic
It seems that by considering the logica docens/logica utens dichotomy, one can adopt a different perspective on critiques of logic throughout history and provide a new categorization of them. In this way, one could say that critiques of logic fall into two categories: one group critiques logica docens, while the other critiques logica utens. Thus, when faced with a critique, one must first determine which category it belongs to in order to provide an appropriate response.
Critiques related to logica docens are themselves divided into two subcategories. Sometimes what is criticized is a specific logical system or some principles of that system. For example, critiques by modern logicians of Aristotelian logic or critiques by relevance or intuitionistic logicians of classical logic fall into this category. Most critiques witnessed in the history of logic belong to this group. However, sometimes critics question the very need for logica docens (regardless of which logical system it may be). Such critics argue that we do not need any logical system at all. One critique against logic in Islamic intellectual history came from scholars of grammar (nahw), who argued that "adhering to grammatical rules suffices and makes logic unnecessary" [Dinani, 2000: 161]. It seems they consider logica utens embedded in language itself and believe that someone who follows linguistic rules is already adhering to logica utens and needs no additional logic.
On the other hand, critiques may target logica utens. These critiques can also take two forms: one might critique the content of logica utens, or one might deny its existence or necessity altogether. However, historical records do not show much evidence of such critiques. Apparently, there has been a consensus that achieving rationality requires using logic and that humans possess reasoning abilities. If there is any disagreement on this matter, it concerns what constitutes this universal human logic and whether it can be revised or improved.
Critiques related to logica docens are themselves divided into two subcategories. Sometimes what is criticized is a specific logical system or some principles of that system. For example, critiques by modern logicians of Aristotelian logic or critiques by relevance or intuitionistic logicians of classical logic fall into this category. Most critiques witnessed in the history of logic belong to this group. However, sometimes critics question the very need for logica docens (regardless of which logical system it may be). Such critics argue that we do not need any logical system at all. One critique against logic in Islamic intellectual history came from scholars of grammar (nahw), who argued that "adhering to grammatical rules suffices and makes logic unnecessary" [Dinani, 2000: 161]. It seems they consider logica utens embedded in language itself and believe that someone who follows linguistic rules is already adhering to logica utens and needs no additional logic.
On the other hand, critiques may target logica utens. These critiques can also take two forms: one might critique the content of logica utens, or one might deny its existence or necessity altogether. However, historical records do not show much evidence of such critiques. Apparently, there has been a consensus that achieving rationality requires using logic and that humans possess reasoning abilities. If there is any disagreement on this matter, it concerns what constitutes this universal human logic and whether it can be revised or improved.
Teaching Logic
Regarding logic, one may ask whether for ordinary people and students alike, familiarity with logica utens, which they already possess to some extent, suffices—or whether there is a need for teaching logic to everyone. Geach argues that what requires public education is logica utens, but those responsible for such education must themselves be proficient in logica docens
(Geach, 1979) . But does logica utens even require teaching? The answer is affirmative. Humans do not perform well in applying logic and often fall into fallacies. The famous Wason test illustrates this issue [Fisher, 2007: 1-2]. Wolenski also highlights other cases where humans commonly make logical errors [Wolenski, 2016: 92]. Teaching logic can strengthen proper logical habits and prevent such errors.
Adopting Logic
This topic derives from a discussion raised by Kripke in a series of lectures in 1974 [Padro, 2015: 35]. Inspired by Lewis Carroll's famous article [Carroll, 1895: 278], Kripke addresses an important issue about logic. Before Kripke, Quine had also used Carroll's article to argue against conventionalism [Quine, 1954: 357].
Kripke's main point is that one cannot start from scratch regarding logic. Teaching certain logical rules is only possible for those who already have some understanding of them. This issue applies at least to two logical rules: modus ponens and universal elimination. In these cases, we cannot stand at a stage prior to adopting them and then subsequently adopt them. However, the number of such logical rules is very limited; for instance, we cannot apply this line of reasoning to existential introduction [Cohnitz & Nicolai, 2021: 7].
As we see here, Kripke’s notion of " adopting logic" does not pertain to adopting logical systems but rather concerns adopting certain logical rules. In other words, it does not address logica docens but rather discusses logica utens. Thus, anyone intending to oppose Kripke must keep this distinction in mind.
Kripke's main point is that one cannot start from scratch regarding logic. Teaching certain logical rules is only possible for those who already have some understanding of them. This issue applies at least to two logical rules: modus ponens and universal elimination. In these cases, we cannot stand at a stage prior to adopting them and then subsequently adopt them. However, the number of such logical rules is very limited; for instance, we cannot apply this line of reasoning to existential introduction [Cohnitz & Nicolai, 2021: 7].
As we see here, Kripke’s notion of " adopting logic" does not pertain to adopting logical systems but rather concerns adopting certain logical rules. In other words, it does not address logica docens but rather discusses logica utens. Thus, anyone intending to oppose Kripke must keep this distinction in mind.
Logical Pluralism
One contemporary issue in logic is whether there is only one correct logic or whether multiple correct logics can exist. Here, unlike the " adopting logic" problem, the focus is on logical systems—meaning we are dealing with logica docens. Consequently, responses must align with this domain. Therefore, a monist arguing against pluralism cannot appeal to shared principles or common practices within human logica utens.
Revising Logic
Another significant topic in logic closely related to pluralism is whether revising and improving logic is possible. Priest has an interesting article on this subject where he examines the possibility of revising both logica docens and logica utens, arguing that such revisions can be rationally justified [Peirce, 1994].
Charles Sanders Peirce's View on Logica Docens/Logica Utens
Charles Sanders Peirce's View on Logica Docens/Logica Utens
Although Peirce frequently used the logica docens/logica utens dichotomy, most of his discussions on this topic are found in sections 9–14 of Chapter 3 in Volume 2 of his collected works [Peirce, 1994].
Peirce states that every human being who reasons has an intuitive understanding of reasoning and distinguishes between good and bad reasoning. However, it seems we also feel that logica utens does not suffice for all reasoning needs. This dissatisfaction drives us toward studying logic.
Peirce dedicates several passages to discussing the nature of logic and states that its most important task is classifying arguments into good and bad ones. He notes that people usually rely on one or more of eight sources for distinguishing between these categories: direct dicta of consciousness, psychology, usages of language, metaphysical philosophy, history, everyday observation, mathematics, and some process of dialectic.
He explains these sources in paragraphs 209–218 but does not adopt any positive stance himself—instead presenting critiques raised against each source. Based on his writings, however, it seems he considers the first source (direct dicta of consciousness) as primarily used by those relying on logica utens, while other sources are typically employed within logica docens. Although he critiques all these sources, he apparently believes we are ultimately compelled to use them for developing logical theories.
What pertains most directly to our discussion is primarily the first source—what appears to be intuitive understanding or some sort of instinctive grasp. Peirce acknowledges criticisms against using such a source but does not explicitly state his own opinion here either; however, he seems sympathetic toward these criticisms.
This sympathy reveals two points: first, Peirce affirms a realist view toward logic—considering logical rules’ truth independent from us—and second, he believes epistemologically we might err in understanding these rules; thus revision—even within logica utens—is permissible.
Another issue concerns adopting logic itself—a matter Peirce fully agrees requires some initial understanding before entering its domain.
Conclusion
Peirce states that every human being who reasons has an intuitive understanding of reasoning and distinguishes between good and bad reasoning. However, it seems we also feel that logica utens does not suffice for all reasoning needs. This dissatisfaction drives us toward studying logic.
Peirce dedicates several passages to discussing the nature of logic and states that its most important task is classifying arguments into good and bad ones. He notes that people usually rely on one or more of eight sources for distinguishing between these categories: direct dicta of consciousness, psychology, usages of language, metaphysical philosophy, history, everyday observation, mathematics, and some process of dialectic.
He explains these sources in paragraphs 209–218 but does not adopt any positive stance himself—instead presenting critiques raised against each source. Based on his writings, however, it seems he considers the first source (direct dicta of consciousness) as primarily used by those relying on logica utens, while other sources are typically employed within logica docens. Although he critiques all these sources, he apparently believes we are ultimately compelled to use them for developing logical theories.
What pertains most directly to our discussion is primarily the first source—what appears to be intuitive understanding or some sort of instinctive grasp. Peirce acknowledges criticisms against using such a source but does not explicitly state his own opinion here either; however, he seems sympathetic toward these criticisms.
This sympathy reveals two points: first, Peirce affirms a realist view toward logic—considering logical rules’ truth independent from us—and second, he believes epistemologically we might err in understanding these rules; thus revision—even within logica utens—is permissible.
Another issue concerns adopting logic itself—a matter Peirce fully agrees requires some initial understanding before entering its domain.
Conclusion
In this paper we did not address the nature of logica utens and logica docens or their relationship. Here, we merely focused on the importance of paying attention to these concepts because, regardless of how we think about their nature or what stance we take toward them, paying attention to them is essential for engaging with many significant logical discussions. This is because everyone in this regard either believes in the existence of this dichotomy or considers it a false and illusory distinction, believing that logic exists only in one sense. It is possible that such a person’s intended logic is logica utens. This position has not had much support throughout history. The need for reasoning and confronting errors and fallacies has convinced most people that we must engage in scientific discussions about logic. However, if someone believes that such a dichotomy does not truly exist and that we are only dealing with logical systems, such a person is either a monist or a pluralist regarding logic. If he is a pluralist, he is faced with the problem of adopting logic and how to justify and explain the commonality of some logical principles among humans. But if he is a monist, he is either a conventionalist or a realist. If he is a conventionalist, as Quine has stated, he has a problem with the application and use of these conventions. And if he is a realist, he needs logical criteria to choose the correct logic that reflects reality and must clarifies his position regarding these criteria and their logical status.
Article Type: Original Research |
Subject:
Logic and Philosophy of Logic (Analytical)
Received: 2025/02/20 | Accepted: 2025/04/11 | Published: 2025/04/30
Received: 2025/02/20 | Accepted: 2025/04/11 | Published: 2025/04/30
References
1. Carroll L (1895). What the tortoise said to Achilles. Mind. 4(14):278-280. [Link] [DOI:10.1093/mind/IV.14.278]
2. Cohnitz D, Nicolai C (2021). How to adopt a logic. Dialectica. 75(4):1-31. [Link]
3. Dinani GE (2000). The adventure of philosophical thought in the Muslim world (Volume 1). Tehran: TARHE No. [Persian] [Link]
4. Fisher J (2007). On the philosophy of logic. Boston: Cengage Learning. [Link]
5. Geach PT (1979). On teaching logic. Philosophy. 54(207):5-17. [Link] [DOI:10.1017/S0031819100024840]
6. Kahneman D (2011). Thinking fast and slow. New York: Farrar, Straus and Giroux. [Link]
7. Lu-Adler H (2018). The nature and place of logic: A history of controversies. In: Kant and the science of logic: A historical and philosophical reconstruction. Oxford: Oxford University Press. p. 31-68. [Link] [DOI:10.1093/oso/9780190907136.003.0003]
8. Padro R (2015). What the tortoise said to Kripke: The Adoption Problem and the epistemology of logic [dissertation]. New York: CUNY Academic Works. [Link]
9. Peirce CS (1994). The collected papers-past masters introduction. Deely J, editor. Cambridge: Harvard University Press. [Link]
10. Priest G (2014). Revising logic. In: The metaphysics of logic. Cambridge: Cambridge University Press. p. 211-223. [Link] [DOI:10.1017/CBO9781139626279.016]
11. Quine WV (1960). Carnap and logical truth. Synthese. 12(4):350-374. [Link] [DOI:10.1007/BF00485423]
12. Wason PC (1966). Reasoning. In: New horizons in psychology. Foss BM, editor. Harmondsworth: Penguin. p. 135-151. [Link]
13. Wolenski J (2016). Logic in the light of cognitive science. Studies in logic grammar and rhetoric. 48(1):87-101. [Link] [DOI:10.1515/slgr-2016-0057]
14. Yousofsani SM (2004). Definition and goal of logic from Muslim logicians' view point. Philosophy of Religion Research. 2(1):111-124. [Persian] [Link]
| Rights and permissions | |
 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |