 It was Łukasiewicz, who as early as 1918 proposed to take seriously other logical values different from truth and falsehood (see Łukasiewicz 1918, 1920). Independently of Łukasiewicz, Emil Post in his dissertation from 1920, published as Post 1921, introduced \(m\)-valued truth tables, where \(m\) is any positive integer. Whereas Post’s interest in many-valued logic (where “many” means “more than two”) was almost exclusively mathematical, Łukasiewicz’s motivation was philosophical (see the entry on  many-valued logic).  He contemplated the semantical value of sentences about the contingent future, as discussed in Aristotle’s De interpretatione. Łukasiewicz introduced a third truth value and interpreted it as “possible”. By generalizing this idea and also adopting the above understanding of the subject-matter of logic, one naturally arrives at the representation of particular logical systems as a certain kind of valuation systems (see, e.g., Dummett 1981, 2000; Ryan and Sadler 1992).