But what makes it special is that at its centre there is a conflict: Somerset (Morgan Freeman) has a knowledge and belief in the classics — Dante's Purgatory, Chaucer, Thomas Aquinas — which equips him with the ability to understand and get to grips with the killer and his crimes, whereas the arrogant and childlike dismissal of such knowledge by Mills (Brad Pitt) leads to a terrible fate for at least two of the main characters. Somerset is stillness itself; Mills is full of that random, uncomprehending "energy" which resents all restraint and priority. One is the old way, the other the new; but having lost its moorings, the new has nowhere to go other than towards its own destruction.  

There are other factors in Se7en which make it interesting for a conservative, not least the fact that, despite having an admittedly warped sense of religiosity, the killer is not explained away in terms of anything as banal as his childhood or background. He sees sin all around him but so, too, does the pessimistic yet still methodical Somerset. "Ernest Hemingway once said ‘the world is a fine place, and worth fighting for'," he intones wearily in voiceover at the end of the film. "I agree with the second part." There is many a conservative, I imagine, who would second that.