The aim of this paper is to analyze J. C. Maxwell’s Treatise on Electricity and Magnetism at the levels of scientific theory and methodology in order to show that it displays certain highly specific epistemic features. We shall start with a reconstruction of the method by means of which is it constituted by briefly delineating the main partial theories utilized up by Maxwell. Next, we shall show that the Treatise also involves potentially also an additional method of theory constitution that was not, however, employed by Maxwell. This method, as we will show next, enables one to employ the Treatise as a ‘structuroanatomic key’ for the reconstruction of those theories in which the Treatise initially originated. Then will provide a critical reflection on Maxwell’s views on the swing from reflections on vortices and ''idlewheel'' particles, which he introduced in the article ''On Physical Lines of Force'' to the examination of the employed Lagrange’s method of analytic mechanic. Finally, we shall employ Maxwell’s Treatise as a ''key'' for the analysis of the more recent discussion of the so-called ''Inconsistency of Classical Electrodynamics.'' and Igor Hanzel