How many heavens does the apostle Paul speak of?

Many of Paul's contemporaries believed that there were seven heavens, physically one above the other, with God at the very top. The lowest heaven was the sphere of the flesh, between the earth and the moon. If someone was written of as 'in the flesh', the cautious scholar will try to establish whether this means the person lived physically on earth or inhabited the realm of the flesh.

Paul wrote that he knew a man caught up in the third heaven, although he could not tell if the man was spiritual or in the body (2 Corinthians 12:2), providing evidence that he also believed in the celestial spheres. He was uncertain whether the man went bodily into the lower heavens or only spiritually.

Another alternative relies on the facts that "third heaven" was a high Gnostic status and that Paul could have been speaking of initiates (spiritual) and those who do not know (in the body - natural or innocent and gullible, not spiritual). It is not clear to me how a man can both be "caught up in" one of the highest Gnostic statuses and yet be an initiate, but if this would have been possible, Paul might not have been speaking of heavens at all, but was probably a Gnostic himself.