" Science proceeds by inference, rather than by the deduction of mathematical proof. A series of observations is accumulated, forcing the deeper question: What must be true if we are to explain what is observed? What " big picture" of reality offers the best fit to what is actually observed in our experience? American scientist and philosopher Charles S. Peirce used the term " abduction" to refer to the way in which scientists generate theories that might offer the best explanation of things. The method is now more often referred to as " inference to the best explanation." It is now widely agreed to be the philosophy of investigation of the world characteristic of the natural sciences. "