One of the outcomes of the Judicature Acts’ reforms of English civil litigation in the nineteenth century was the separation of ‘substance’ from ‘procedure’, by introducing rules of court that were expected to apply trans-substantively, in contrast to the previous forms of action. This was not an express central aim of the reformers, who may also have been influenced by the then concurrent creation of the American system of federal courts and their civil procedure. The chapter identifies the historical, philosophical, and ideological buttresses of the trans-substantive nature of procedural rules in the English legal system, and how trans-substantivity itself differs from the cognate values of generality and uniformity. It then explores whether any one of these concepts is still used, or useful, in English civil procedure.