The principles of Leibniz 's logic and , arguably , of his whole philosophy , reduce to two :
Leibniz enunciated the principal properties of what we now call conjunction , disjunction , negation , identity , set inclusion , and the empty set .
The principles of Leibniz 's logic and , arguably , of Leibniz 's whole philosophy , reduce to two :
Leibniz enunciated the principal properties of what we now call conjunction , disjunction , negation , identity , set inclusion , and the empty set .