On the bookshelf behind me is a volume I return to time and time again. ‘The consequences of ideas’ by R.C. Sproul, is in many ways a depressing read. Starting with the Ancient Greek philosophers such as Pythagoras, Plato and Aristotle, he works his way through Descartes, Locke, Hume and Marx, and culminates with Nietzsche, Darwin and Freud. With such an infamous bunch–which gets increasingly worse as you progress–you might wonder why I return to it.