Uniquely occupies three roles simultaneously: the man who suffered, the psychiatrist who observed, and the philosopher who theorized. The triple perspective is the book's source of authority and its occasional weakness — Frankl can seem to have processed his experience too cleanly, too usefully. But this may be the point: the processing is itself the survival. He did not just live through the camps — he made something of them, and that making was already underway in the camps themselves.