 Tarski correctly identified these two features as key components of the notion of logical consequence as entertained by philosophers and mathematicians of his time (and also today). But the question arises: why these two features and not others? In particular, through which (historical) processes have they come to constitute the conceptual core of the notion of logical consequence? These questions are even more pressing in view of the fact that both features have been challenged as correct renditions of the conceptual core of logical consequence — Etchemendy (1990) challenged the centrality of formality and (ST); Fields (2008) challenged the centrality of necessary truth-preservation in view of the semantic paradoxes.