This next led me to think of Jesus' words to his disciples, warning them that the world would hate them because of Jesus. I believe there may be a small connection between how the world will perceive the way that a believer thinks, in comparison to a "regular" person.
The second person that then came to mind, in regards to being considered insane, was Alistair Crowley, the famous British occultist from the mid 1900's. This man, clearly, was on the opposite end of the spectrum, from the Apostle Paul. Crowley certainly had his share of learning, but his was not an education in godliness and love, but rather literally, the opposite. Crowley spent his inherited fortune and literal lifetime inventing and discovering every form of magic and perversion known to man. In the end, Crowley became a babbling madman, literally. The later audio recordings of him reveal a literal blithering idiot, completely incoherent.
So what is the difference? Paul was called a madman, due to his cogent, coherent, moving intelligence, even though it was contrary to "normal" thought. Crowley was considered a madman because he literally appeared to be insane. Literally incoherent and irrational.
This is a good example of love of God and love of neighbor moving one man to life and beauty, while the pursuit of lust, power and debauchery led another man to insanity.
I'm not exactly sure what the value of this thought experiment is, but it came together in a somewhat intriguing fashion. I'd love to hear your comments/thoughts.