I currently hold 2 undergraduate diplomas, 2 undergraduate degrees and 2 master's degrees. If I have the stamina, I'll do second doctorate.

The third guy has 2 PhDs one in Education and the other in Theology and is currently in KCL. Again, he is a giant in field of Religion in Education. I see nothing wrog in doing 2 PhDs if you have the stamina. I'll probably do it.

I think it really depends on the direction life takes you. I have been associated with three academics who holds 2 PhDs respectively. The first orginally obtained his PhD in Psychology from Essex and then moved into the field of music obtaining a second PhD in Music in a 5* rated UK music department. If I mention the Uni. I'll possibly give away his identity. This guy is currently Professor of Music and a BIG name in the field worldwide as I write. The second guy is currently Professor of Theology, and used to be Principal of one of the Colleges in Oxford. He originally took his PhD in Quantum Physics from Oxford before doing his bachelors and PhD in Theology, also at Oxford. Some people would possibly know whom I'm talking about. Why? the guy is hotly in debate with Richard Dawkins on God's Existence. He is known worldwide for his excellence not just in the area of Science & Religion, but also in Systematic Theology.