Do We See Through a Microscope?

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

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

3. I. UOD • UOD’s importance to the realism debate • Issues with UOD • Maxwell on UOD • Van Fraassenon UOD

4. 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.

5. 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.

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

7. I.D. Van Fraassen on UOD

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

9. 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.

10. Dense Bodies

11. Grids

12. 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?

13. A. Observability

14. 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. • Microscopistsdistinguish real phenomenon from a mere artefact; realists distinguish a real though unobservable entity from a mere tool of thought.

15. Relevant to Realism?

16. 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.