Do We See Through a Microscope? Kareem Khalifa Department of Philosophy Middlebury College

Overview The Observable-Unobservable Distinction (UOD) Hacking on UOD Objections to Hacking

I. UOD UOD’s importance to the realism debate Issues with UOD Maxwell on UOD Van Fraassen on UOD

I.A. UOD’s Importance to the Realism Debate Constructive Empiricism: science aims to have empirically adequate theories. A theory is empirically adequate if and only if what it says about observable entities is true. So, if constructive empiricism is true, then science aims for theories that say only true things about observable entities.

I.B. Issues with UOD Any distinction between unobservable and observable entities is arbitrary. If UOD is arbitrary, then what is unobservable is as knowable as what is observable. If what is unobservable is as knowable as what is observable, then science should aim for theories that say true things about both observable and unobservable entities, i.e. realism is true. So, realism is true.

I.C. Maxwell’s Arguments Mediation Objection Mutation Objection

I.D. Van Fraassen on UOD

II. Hacking on UOD Main Thesis Microscope Argument Examples of Robusteness

The Microscope Argument According to scientific practice, an entity is observable if there is an accurate model of the interactions between the specimen and the detector’s imaging radiation. According to scientific practice, a model of these interactions is accurate if its results are robust, and we can use the detector’s results to manipulate the specimens represented by that model. It is possible for a model of the interactions between a specimen and a detector’s imaging radiation to be robust and manipulable, yet human beings with normal vision could not have seen the specimen with the naked eye. So, van Fraassen’s account of observability does not accord with scientific practice.

Dense Bodies

Grids

III. Objections to Hacking Is this really observability? Is this just the No Miracles Argument warmed over? Is this is relevant to the realism debate?

A. Observability

B. Robustness and No Miracles There is no distinction between observational and theoretical vocabulary. (145). This doesn’t concern explanation. (146) We have no theory which predicts some wide range of phenomena. Microscopists distinguish real phenomenon from a mere artefact; realists distinguish a real though unobservable entity from a mere tool of thought.

Relevant to Realism?

I. Recap The Unobservable-Observable Distinction is relevant to the realism debate. While Hacking’s account of observability may clarify that distinction…. …it may not help to resolve the debate.