 Theories of consequence explicitly acquired an autonomous status only in the 14th century, when treatises specifically on the concept of consequence began to appear; but some earlier investigations also deserve the general title of ‘theories of consequence’, in view of their scope, sophistication and systematicity. Taken as a whole, medieval theories of consequence represent the first sustained attempt at adopting a sentential/propositional  perspective[3]  since the Stoics in Greek antiquity, and — unlike Stoic logic, which had little historical influence — provide the historical background for subsequent developments leading to the birth of modern logic in the 19th century. Indeed, it may be argued that the medieval concept of consequentia (in its different versions) is the main precursor of the modern concept of logical consequence.