Stoics on pain

Brennan describes the Stoic conception of pain as one of the four basic kinds of emotion:

Pain is an opinion that some present thing is a bad of such a sort that we should be downcast about it.
[Cambridge Companion to the Stoics, p.270]

Why so little attention to physical evil?

One hypothesis on why Medieval and other early writers ignore pain to a large degree:

In these centuries...prior to the development of medicine and its pain-killing or controlling drugs, and when very severe penalties, imposed by Church and State alike, were commonly acceptable, the problems of physical evil do not appear to have been taken as seriously as they are by contemporary thinkers. [Connellan, Why Does Evil Exist? p.9]