The inductive or hypothetic conclusion, therefore, stands to one of its premisses in the relation of a deductive or syllogistic premiss to its conclusion, the second premiss of the induction or hypothesis remaining a premiss in this explaining syllogism. It is in fact a sufficient definition of a scientific inference to say that it is the inference of one of the premisses of a syllogism from the other premiss and from the conclusion. If fact, every such inference is valid, that is to say, lends an additional probability to the proposition inferred, altho’ the fact indicated by this proposition may still remain entirely unknown or even grossly improbable.