Logic as a Methodological Discipline Gil Sagi  Abstract This essay offers a conception of logic by which logic may be considered to be exceptional among the sciences on the backdrop of a naturalistic outlook. The con- ception of logic focused on emphasises the traditional role of logic as a methodology for the sciences, which distinguishes it from other sciences that are not method- ological. On the proposed conception, the methodological aims of logic drive its definitions and principles, rather than the description of scientific phenomena. The notion of a methodological discipline is explained as a relation between disciplines or practices. Logic serves as a methodological discipline with respect to any theo- retical practice, and this generality, as well as logic’s reflexive nature, distinguish it from other methodological disciplines. Finally, the evolution of model theory is taken as a case study, with a focus on its methodological role. Following recent work by John Baldwin and Juliette Kennedy, we look at model theory from its inception in the mid-twentieth century as a foundational endeavour until developments at the end of the century, where the classification of theories has taken centre-stage. 1 Introduction: Is Logic Special? Recent discussions on the nature of logic question its exceptional status among the sci- ences. This Quinean outlook has recently been expressed by Hjortland: Logic isn’t special. Its theories are continuous with science; its method con- tinuous with scientific method. Logic isn’t a priori, nor are its truths analytic truths. Logical theories are revisable, and if they are revised, they are revised on the same grounds as scientific theories.” (Hjortland, 2017, p. 632)  This paper was presented to the London Group for Formal Philosophy and the Jerusalem Working Group in Logic. I’d like to thank the members of both groups for a useful discussion. I’d also like to thank the following for helpful comments: Tim Button, Rea Golan, Balthasar Grabmayr, Catherine Herfeld, David Kashtan, Juliette Kennedy, Arnon Keren, Aviv Keren, Ran Lanzet, Talia Leven, Carlo Nicolai, Filippos Papagiannopoulos, Lavinia Picollo, Carl Posy, Daniel Statman and Florian Steinberger.) 1