Few matters have evoked more theological controversy than the identity of Paul's 'thorn in the flesh'.

The information given suggests that the affliction dated from his 'third heaven' experience (v2). It was chronic, probably intermittent (v8), peculiar to Paul, and caused him pain, weakness and embarrassment, whilst enabling him to continue with his ministry.

The views most commonly put forward include persecution, temptation and physical illness.

While 'messenger of Satan' (v7) could imply a human agent, it is singular rather than plural (see Nu 33:55), making persecution unlikely as the sole explanation. Paul seems to address persecution later as a separate issue (v10).

Temptation is a possibility, but temptation was by no means peculiar to Paul, nor best described by the metaphor employed.

The connection in the ancient mind between demonic activity and physical disease along with the use of the word 'thorn' (skolops) has led the majority of commentators to suggest some form of chronic medical disorder: hysteria, migraine, depression, sciatica, malunited fractures, arthritis, leprosy or (most popularly) malaria, epilepsy or an eye condition.

Any of these diagnoses is possible, but each poses problems. Malaria, for example, while endemic in Asia Minor in the first century, would have been a common complaint and probably not worth singling out. By contrast, adult onset epilepsy is rare, and by its very nature would surely have prompted specific mention elsewhere in Scripture. The apostle clearly did suffer from an eye disorder of some kind (see below) but the time of onset implied in this passage (some time after the blinding light at his conversion), makes this also an unlikely proposition.

Luke is unable to decide from the details presented, and while perhaps inviting the wrath of all sides, admits he doesn't know the answer.