Advertisement

Practical Inference—A Formal Analysis

  • Sjoerd Zwart
  • Maarten Franssen
  • Peter Kroes
Chapter
Part of the Philosophy of Engineering and Technology book series (POET, volume 31)

Abstract

Most engineering reasoning in practice is about how to achieve some predetermined end. Despite its paramount importance, this form of reasoning has hardly been investigated in the literature.a The aim of this paper is therefore to explore the question to what extent technical norms can be said to have a truth-value, and under what conditions practical inferences are deductively valid. We take technical norms to be sentences of the form ‘If you want A, and you are in a situation B, then you ought to do X’. Von Wright’s standard example of making a hut habitable is our paradigm for practical inferences, where an obligation to act is deduced from an intention to realize an end, and an empirical constraint on how this end can be achieved. Our instrument of analysis is dynamic logic (PDL), since actions are aimed at changing the world. PDL already suffices to provide truth-conditions for technical norms. To accommodate the obligation in practical inferences we draw on John Jules Meyer’s deontic version of PDL. By paraphrasing ‘person P wants’ with ‘person P imposes an obligation on herself,’ we can give a plausible definition of the validity of practical inferences. In the discussion section, we address the issues of the reliability instead of truth-value of technical norms, and of the defeasibility of practical inferences as they occur in engineering practice.

Keywords

Engineering means-end knowledge From intentions and constraints to obligations to act Practical inferences and logical validity Technical norms and truth conditions Deontic dynamic logic semantics 

References

  1. Broersen, J. (2004). Action negation and alternative reductions for dynamic deontic logics. Journal of Applied Logic, 2(1), 153–168.CrossRefGoogle Scholar
  2. Broome, J. (2002). Practical reasoning. In J. Bermúdez & A. Millar (Eds.), Reason and nature: Essays in the theory of rationality (pp. 85–111). Oxford: Oxford University Press.Google Scholar
  3. Harz, M. (2007). Zur Logik der technologischen Effektivität. Cottbus: Brandenburgischen Technischen Universität. https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/3738.Google Scholar
  4. Herzig, A., & Lorini, E. (2010). A dynamic logic of agency I: STIT, capabilities and powers. Journal of Logic, Language and Information, 19(1), 89–121. https://doi.org/10.1007/s10849-009-9105-x.CrossRefGoogle Scholar
  5. Hughes, J., Kroes, P., & Zwart, S. (2007). A semantics for means-end relations. Synthese, 158(2), 207–231.CrossRefGoogle Scholar
  6. Irvine, W. B. (2006). On desire: Why we want what we want. Oxford: Oxford University Press.Google Scholar
  7. Meyer, J.-J. (1988). A different approach to deontic logic: Deontic logic viewed as a variant of dynamic logic. Notre Dame Journal of Formal Logic, 29(1), 109–136.CrossRefGoogle Scholar
  8. Meyer, J.-J. C., van der Hoek, W., & van Linder, B. (1999). A logical approach to the dynamics of commitments. Artificial Intelligence, 113(1), 1–40.CrossRefGoogle Scholar
  9. Niiniluoto, I. (1993). The aim and structure of applied research. Erkenntnis, 38(1), 1–21. https://doi.org/10.1007/BF01129020.CrossRefGoogle Scholar
  10. Segerberg, K. (1980). Applying modal logic. Studia Logica, 39(2–3), 275–295.CrossRefGoogle Scholar
  11. Von Wright, G. H. (1963a). Norm and action: A logical enquiry. London: Routledge & Kegan Paul.Google Scholar
  12. Von Wright, G. H. (1963b). Practical inference. The Philosophical Review, 72(2), 159–179.CrossRefGoogle Scholar
  13. Von Wright, G. H. (1963c). The varieties of goodness. London: Routledge & Kegan Paul.Google Scholar
  14. Von Wright, G. H. (1972). On so-called practical inference. Acta Sociologica, 15(1), 39–53.CrossRefGoogle Scholar
  15. Von Wright, G. H. (1999). Deontic logic-as I see it. In P. McNamara & H. Prakken (Eds.), Norms, logics and information systems: New studies in deontic logic and computer science, Artificial intelligence and applications (Vol. 49, pp. 15–25). Amsterdam: IOS Press.Google Scholar
  16. Wang, Y. (2016). A logic of goal-directed knowing how. Synthese, 1–21. https://doi.org/10.1007/s11229-016-1272-0
  17. Wieringa, R. J., & Meyer, J.-J. C. (1993). Actors, actions, and initiative in normative system specification. Annals of Mathematics and Artificial Intelligence, 7(1–4), 289–346.CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Delft University of TechnologyDelftThe Netherlands
  2. 2.Eindhoven University of TechnologyEindhovenThe Netherlands

Personalised recommendations