Abstract

Recent philosophy of science has seen a growing interest in scientific models and, in particular, in the question of how models represent the world. And yet three-dimensional physical models, like wax anatomical models or Crick and Watson’s famous model of DNA , have been largely ignored by philosophers of science, despite recent historical studies demonstrating the importance of physical models in many sciences.

In this talk, I will offer an analysis of physical models based on Kendall Walton’s ‘make-believe’ theory of art. To do so, I will also draw on an empirical study of the use of a well-known type of physical model: the ‘ball-and-stick’ molecular models familiar to many from school science classes. According to Walton, works of art function as props in games of make-believe, like children’s dolls or toy trucks. I will analyse physical models in the same way. Just as a child imagines a plastic doll to be a baby so, I shall argue, scientists imagine the balls and sticks of a molecular model to be atoms and bonds.

Children participate in their games of make-believe: a child playing with a doll not only imagines it to be a baby; she also imagines looking at a baby, picking the baby up and feeding it. Similarly, I will argue, scientists participate in the games they play with molecular models, imagining themselves looking at molecules, twisting them around and pulling them apart. By manipulating molecular models, I suggest, scientists perform imagined experiments on molecules.