Deliberative indispensability argument
The deliberative indispensability argument is an argument for normative realism defended by David Enoch, most prominently in his 2011 book Taking Morality Seriously. Enoch was inspired by other indispensability arguments in the philosophy of mathematics. These arguments often rely on the explanatory indispensability of mathematics to support mathematical realism. However, Enoch aimed to expand the scope of indispensability arguments beyond explanatory indispensability, arguing that indispensability to deliberation is a good reason to believe in normative truths.
The argument claims that deliberation is rationally non-optional because deliberating is required to rationally act in the world. It further claims that the only way to make sense of deliberation is with irreducibly normative truths. This is because deliberation seems to be the search for objectively right answers about what is the correct decision to make in a given situation. The argument concludes that it is justified to believe in irreducibly normative truths. Counterarguments include the idea that deliberation does not require objectively right answers because it could be based on subjective desires, and that deliberation is not adequately connected to the truth to justify beliefs.
Background
[edit]The deliberative indispensability argument is an argument for robust realism about normative and moral truths. This is the view that normative and moral truths exist and they are objective and irreducibly normative. In other words, they are true as a matter of fact—not a matter of personal preference or opinion—and they cannot be reduced to descriptive natural facts.[1]
One argument against robust realism from Gilbert Harman is that moral truths cannot explain any empirical observations. Harman contrasted moral claims with scientific claims, like claims about electrons. According to Harman, the existence of electrons is required to explain various observations such as trails left in cloud chambers. In contrast, people's moral viewpoints can be explained by their upbringing and culture, so moral facts are not necessary to explain moral psychology or behavior.[2]
David Enoch formulated the deliberative indispensability argument in part to respond to this point by Harman.[3] It was inspired by other indispensability arguments from the philosophy of mathematics. These arguments often support mathematical realism based on mathematics' explanatory indispensability to science, but Enoch aimed to expand indispensability considerations beyond scientific explanation. He argued that normative truths are indispensable to deliberation and that deliberative indispensability is as good an argument for their existence as explanatory indispensability would be.[4]
Argument
[edit]The argument is one example of an indispensability argument. In general, indispensability arguments work by defending their conclusion on the basis that it is indispensable for some purpose or project.[5] In formulating his own version of the argument, Enoch considered why indispensability to explanation can support a conclusion but indispensability to other projects, like sorcery, cannot. He argued that this is because explanation is intrinsically indispensable in the sense that it is rationally non-optional to engage in the project of explanation to understand and act in the world. By contrast, attempts at sorcery are an optional project.[6]
Enoch's argument, therefore, introduces a distinction between an entity being instrumentally indispensable to carry out a project, and the intrinsic indispensability of the project itself. The entity is instrumentally indispensable because it is required to carry out the project successfully. The project is intrinsically indispensable because it is rationally non-optional. According to Enoch, both of these forms of indispensability are required for an indispensability argument to be successful.[7]
With this distinction in place, Enoch states the deliberative indispensability argument in Taking Morality Seriously as follows:[8]
- If something is instrumentally indispensable to an intrinsically indispensable project, then we are justified in believing that that thing exists.
- The deliberative project is intrinsically indispensable.
- Irreducibly normative truths are instrumentally indispensable to the deliberative project.
- Therefore, we are justified in believing that there are irreducibly normative truths.
This argument relies on the idea that deliberative indispensability can justify beliefs in a similar way to explanatory indispensability. Enoch argues that explanation and deliberation are both rationally non-optional so can both support indispensability arguments. He challenges opponents of this idea to explain how explanation and deliberation are different so that only explanation can support indispensability arguments.[9]
The argument also relies on the idea that irreducibly normative truths are indispensable to deliberation. Enoch states that deliberation is the attempt to find what it is best to do or think in a given situation. He argues that the act of deliberation assumes that there are right answers about what is the best thing to do, which can only be accounted for if there are irreducibly normative truths.[10]
Analysis and counterarguments
[edit]One area of debate about the argument concerns the idea that irreducibly normative truths are indispensable to deliberation. Enoch defended this by attempting to show that no other view can account for the experience of deliberating, which seems to be a search for objectively right decisions. In particular, he argues that normative truths searched for in deliberation must be irreducible because they are too different to be reduced to ordinary natural or scientific facts.[11] An alternative view claims that deliberation is a search for correct answers based on subjective desires rather than objective truth.[a] However, according to Enoch and others such as Thomas Nagel, it is often rational to question our desires so they alone cannot provide definitive answers to deliberation.[12]
The deliberative indispensability argument is a pragmatic defense of deliberation as a source of true beliefs. It supports its conclusion on the basis that deliberation is of such great practical value that it is non-optional for rational beings.[13] One advantage of this account is that it explains how deliberation can be a basic source of knowledge without leading to an infinite chain of justification; deliberation does not need any justification because it is rationally non-optional.[14] One counterargument, however, argues that a pragmatic defense relying on practical value is not enough to justify beliefs, because justified beliefs require theoretical value and a method that is directed at the truth.[15][b]
A related dispute is about how deliberation can provide a belief-forming method. One way of describing explanatory indispensability arguments is as justifying the use of inference to the best explanation as a basic belief-forming method because explanation is rationally non-optional.[16] However, according to Alex Worsnip, Enoch did not provide an analogous belief-forming method based on deliberation, and therefore is missing a key element of an indispensability argument.[17] Matt Lutz argues that the method justified by Enoch's deliberative indispensability argument is reliance on normative intuitions. This means that it is justified to use intuitions to form the belief that there are normative truths.[16]
Notes
[edit]- ↑ For an example of this type of counterargument, see Lenman 2013.
- ↑ For examples of this type of counterargument, see McPherson & Plunkett 2015 and Cline 2016.
References
[edit]Citations
[edit]- ↑ Lenman 2013, pp. 835–836; Behrends 2012, pp. 146–147; Faraci 2012, pp. 259–260.
- ↑ Lutz 2022, p. 119; Vesper 2025, p. 28; Chrisman 2023, pp. 5, 22.
- ↑ Lutz 2022, p. 119.
- ↑ Sinclair & Leibowitz 2016, pp. 15–16.
- ↑ Cline 2016, p. 3240.
- ↑ Sinclair & Leibowitz 2016, p. 15; Cline 2016, p. 3240.
- ↑ Sinclair & Leibowitz 2016, p. 15; McPherson & Plunkett 2015, pp. 107–108.
- ↑ Enoch 2011, p. 83; Sinclair & Leibowitz 2016, p. 16.
- ↑ Worsnip 2016, p. 226; Cline 2016, p. 3236.
- ↑ Vesper 2025, p. 30; Cline 2016, p. 3241; Chrisman 2023, p. 22.
- ↑ Cline 2016, p. 3241.
- ↑ Vesper 2025, p. 32.
- ↑ Vesper 2025, pp. 29–30.
- ↑ Stewart 2024, p. 240; Lutz 2022, pp. 125–127.
- ↑ Vesper 2025, p. 33; Lutz 2022, pp. 127–128; Chrisman 2023, p. 23.
- 1 2 Molina 2026, p. 463.
- ↑ Lutz 2022, p. 121; Worsnip 2016.
Sources
[edit]- Behrends, Jeff (2012). "Review of Taking Morality Seriously: A Defense of Robust Realism". The Review of Metaphysics. 66 (1): 146–148. ISSN 0034-6632. JSTOR 41635563.
- Chrisman, Matthew (2023). What Is This Thing Called Metaethics?. Routledge. pp. 21–23. ISBN 978-1-003-20589-0.
- Cline, Brendan (2016). "Against Deliberative Indispensability as an Independent Guide to What There Is". Philosophical Studies. 173 (12): 3235–3254. doi:10.1007/s11098-016-0661-z. ISSN 0031-8116. PhilPapers CLIADI.
- Enoch, David (2011). Taking Morality Seriously. Oxford University Press. ISBN 978-0-19-957996-9.
- Faraci, David (2012). "Review of Taking Morality Seriously: A Defense of Robust Realism". The Journal of Value Inquiry. 46 (2): 259–267. doi:10.1007/s10790-012-9329-x. ISSN 0022-5363. PhilPapers FARDET.
- Lenman, James (2013). "Deliberation, Schmeliberation: Enoch's Indispensability Argument". Philosophical Studies. 168 (3): 835–842. doi:10.1007/s11098-013-0214-7. ISSN 0031-8116. JSTOR 42920392. PhilPapers LENDSE.
- Lutz, Matt (2022). "In Defense of Deliberative Indispensability". Pacific Philosophical Quarterly. 103 (1): 118–135. doi:10.1111/papq.12341. ISSN 0279-0750.
- McPherson, Tristram; Plunkett, David (2015). "Deliberative Indispensability and Epistemic Justication" (PDF). In Shafer-Landau, Russ (ed.). Oxford Studies in Metaethics. Vol. 10. Oxford University Press. ISBN 978-0-19-873869-5.
- Molina, Yohan (2026). "Taking Morality Directly". The Journal of Value Inquiry. 60 (3): 459–467. doi:10.1007/s10790-024-10003-y. ISSN 0022-5363.
- Sinclair, Neil; Leibowitz, Uri D. (2016). "Introduction: Explanation in Ethics and Mathematics". In Sinclair, Neil; Leibowitz, Uri D. (eds.). Explanation in Ethics and Mathematics: Debunking and Dispensability. Oxford University Press. pp. 1–20. ISBN 978-0-19-877859-2.
- Stewart, Andrew (2024). "The Normative, the Practical, and the Deliberatively Indispensable". The Journal of Value Inquiry. 58 (2): 235–255. doi:10.1007/s10790-021-09877-z. ISSN 0022-5363.
- Vesper, Achim (2025). "No Normative Output Without Normative Input? An Examination of the Argument from Deliberative Indispensability". International Journal for the Semiotics of Law. 38 (1): 25–38. doi:10.1007/s11196-024-10214-3. ISSN 1572-8722.
- Worsnip, Alex (2016). "Explanatory Indispensability and Deliberative Indispensability: Against Enoch's Analogy". Thought: A Journal of Philosophy. 5 (4): 226–235. doi:10.1002/tht3.220. ISSN 2161-2234.