How do we know Paul wrote his own letters?

A:

The seven epistles that are generally considered to be genuine (Romans, 1 Corinthians, 2 Corinthians, Philemon, Galatians, Philippians and 1 Thessalonians) ring true. A.Q. Morton assumed that Paul wrote Galatians and did a computer study of the style of the remaining letters, using that epistle as a reference. His analysis found that only Romans, 1 and 2 Corinthians, and Philemon contain exactly the same writing style as Galatians - although at this stage, most scholars maintain that Paul did write seven of the epistles attributed to him. Thus, whether Paul personally wrote out the letters or used a secretary, we can at least say that some (probably seven) of the epistles in the New Testament really are his.

Stanley E. Porter (As It Is Written) looks at the epistles to discover how well educated Paul would have been. He concludes that Paul had a moderately good education in the Greek system and also, based on claims made in Acts of the Apostles, learnt under Gamaliel in Jerusalem. He would have been well capable both of dictating and also writing his own letters.

Through the epistles, we see that Paul took no money and performed manual work in order to help support himself. It would seem strange that he would perform arduous, low-paid manual work and then pay a skilled scribe to write under his dictation. Unless otherwise proven, Paul wrote his own letters.