 It is not, however, clear whether authors who summarily refer to probable premises only intend endoxa in their definitions of dialectical syllogism, or whether they operate, like Albert of Cologne, with a broader notion of probable premise. Albert (Logica, I, 4, 2, 278) speaks with respect to the dialectical syllogism about premises which are always or most often (in pluribus) true. There was also some discussion about the epistemic status of the argumentative scheme of the dialectical syllogism and the conclusions from probable premises. The common assumption was that the dialectic syllogism is an indubitably valid deductive scheme, but that probable premises produce only probable conclusions or opinions (Buridan, Quaestiones, 19; Buridan, Summulae, 347).