In October 2025, PJM associate editor Armin Mattes presented a paper on “‘The Mutability of Meaning’: James Madison and Conceptual Change during the Age of Revolution” at the  Pennsylvania Historical Association Annual Meeting. Mattes explored Madison’s late-in-life efforts to correct what he perceived as errors and misunderstandings of terms in arguments presented by his correspondents. Madison saw doing so as important to avoid having “important errors . . . produced by mere innovations in the use of words & phrases . . . in the exposition of laws, & even of Constitutions” (JM to Converse, 10 March 1826). Madison became so concerned with this topic that sometime in retirement he even started outlining an essay on the “Causes of Innovations in Language.” Mattes’s work applies the methodology of Begriffsgeschichte (a German historiographical method with a special emphasis on connections between historical developments and conceptual change) to offer fresh insights into questions such as the radicalism of the revolutionary era in the United States and the pitfalls of “originalism.”