Logical operators are a central focus of logicians, and two important books with innovative thoughts on logic include Begriffsschrift (1879) by Gottlob Frege and The Laws of Thought by George Boole in 1854. The contribution of Boolean Algebra is memorable for the formalization of an algebra with the logical connectives AND, OR, and NOT. Before 1854, were there other logical operators, and if such an operator(s) existed what was the motivation for their creation?
Which unary or binary logical operators existed in logic before 1854 besides 'and', 'or', and 'not'?
-
2Why 1878? And existed how, with a special symbol? If-then, not-and, not-or, exclusive or, are commonplace in natural language. Material implication goes back to Philo the Dialectician (c. 300 BC), Leibniz had symbols for it, its reverse and the biconditional, Venn had a symbol for symmetric difference, a.k.a. exclusive or, see Origins of Boolean Algebra in the Logic of Classes. – Conifold Nov 5 '20 at 6:44
-
1You'll love Lambert's list (1782), although the language of "logical operators" is so anachronistic I am not sure there were any even in 1878. – Conifold Nov 5 '20 at 7:09
-
You may have a look at the logic of the Stoics. – Floridus Floridi Nov 5 '20 at 8:29
-
See : Wolfgang Lenzen, Leibniz’s Logic and the Cube of Opposition (Log Uni, 2016) for some example regarding Leibniz. – Mauro ALLEGRANZA Nov 5 '20 at 8:57