   Both Mereology and Ontology presuppose a deeper logical layer, comprising a propositional logic of connectives like ‘if’, ‘not’ and ‘and’, and the as yet unexplicated logic of the quantifiers ‘for all’ (‘\(\forall\)’) and ‘for some’ (‘\(\exists\)’). Having settled Ontology on an axiomatic basis, Leśniewski turned to the axiomatization of this. He originally spoke of the “theory of deduction”, which was the name Whitehead and Russell used for the propositional calculus, but because they did not introduce a logic of quantifiers until later, he coined the term ‘Protothetic’, from the Greek for ‘first theses’. It is characteristic of Leśniewski’s logic that he introduces quantifiers in the most basic part of his logic, even before names are introduced. This is unlike most modern theories, which introduce quantifiers only when names and predicates are brought in. It leads to questions about the nature of quantification in Leśniewski which we will revisit below.