The enigma of simplicity

Many scientists believe that simplicity is a crucial element in their quest for knowledge. The order, which is found in chaos, it is thought, facilitates understanding, prediction and intervention. This seems particularly proper in statistical science. Simplicity seems to be related to inductive power. Some even hold simplicity as a sign of beauty and assign it intrinsic value (see Derkse, 1992). Simplicity has many faces. Still, exactly how simplicity is used in scientific reasoning remains enigmatic. Until recently, simplicity remained part of the realm of metaphysics. Recent arguments in the philosophy of science, statistics and econometrics generated wide agreement that the role of simplicity in scientific reasoning is in need of clarification. A multidisciplinary conference was organized and held at Tilburg University in January 1997 to help clarify the definition and role of simplicity in scientific reasoning. The fruits of the conference are presented in this volume of papers. The idea that simplicity matters in science is as old as science itself. Consider Occam’s razor, ‘entia non sunt multiplicanda praeter necessitatem’: entities are not to be multiplied beyond necessity. A problem with Occam’s razor is that nearly everybody seems to accept it, but few are able to define its exact meaning and to make it operational in a non-arbitrary way. Hence, the theme for this volume might well be summarized by the general question of how to clarify the enigma of simplicity in scientific inference. This leads to several specific questions, namely: