Iulian Toader

The general topic of this project is the role of fiction in science, and its focus is on idealization as a means for understanding the physical world. More particularly, the project is concerned with the contribution of scientific idealization to providing objective and explanatory knowledge of natural phenomena, that is, knowledge that ascertains their mind-independent reality and helps us understand why they occur in the way they do.

It is typically acknowledged that things like hard ball gas molecules, frictionless planes, flat spacetimes, infinite velocities, and the like, help us understand the behavior of physical systems. For example, frictionless planes are sometimes thought to be explanatory because their use neglects certain forces acting on the sliding bodies. Hard ball gas molecules help us understand the behavior of gas molecules by neglecting the inelastic character of their dynamical interaction under collision. But what makes these fictions capable of bringing about scientific understanding? Furthermore, what makes such fictions capable of providing scientific objectivity?

At a first glance, objectivity does not seem to require that the objects of foundational physics, like quarks, gluons, or other such things, be real, rather than fictional. Some think that what is required for objectivity is that those theories that purport to explain the behavior of these objects be, in a certain sense, invariant. This focus on invariance is compatible with the view that these objects may be fictional, rather than real. Even if quarks, gluons, or other such things, are not what the real world is actually made of, we can still attain objectivity as long as our theories are invariant. But is invariance sufficient for objectivity? And could this view pass the test of concrete cases from foundational physics?

These are the main questions that this project attempts to address. Its first part is a critical evaluation of current views on scientific idealization, while its second part proposes and defends a new account of how idealization serves both objectivity and understanding. This new account overcomes Weylean skepticism, which is the view that science, to the extent that it strives to attain objectivity may do so only at the expense of understanding, and to the extent that it aims at understanding may do so only by sacrificing objectivity.