 All that William of Sherwood can offer to characterize confused supposition is to say that it is had when a term supposits for many, then resorting to examples for its divisions. Peter of Spain tries harder: “Confused supposition is taking a common term in place of many by means of a universal sign” (tr. Copenhaver, p.  249),[26]  and confused and distributive when it supposits for all. But this is still unclear, and eventually a solution was found, in the doctrine of ascent and descent. Call the individual things falling under a general term its “inferiors”, and call the singular proposition resulting from a general proposition by replacing a general term (with its qualifier) by a term with discrete supposition for one of its inferiors, one of the proposition's “singulars”. Then the inference from a general proposition to one of its singulars is called “descent”, the converse inference, “ascent”. If descent under a term is valid, or at least is valid without changing the rest of the proposition, it is called “mobile”, otherwise “immobile”. Walter Burley, William of Ockham and their followers could then define the three modes of common personal supposition as follows: