Lecture slides from 6 May 2004

---

Realist accepts theory:  EVERYTHING the theory claims is true.

Antirealist accepts theory:  The theory FITS all the observables (and will continue to do so as we get more data...)

---

Why be an antirealist?

How much can I really conclude from the observables?

(According to van Fraassen, observable = could be detected with unaided senses.)

Consider the "Black Box"

---

Assumptions:

• The world is a certain way (as described in theory).
• If the world is that way, interaction of rays and box gives us information about what's in the box.

**If our observations fit the theory, does that prove the theory?

---

Are we observing the targets in the box?

Do we make observations with a microscope?

Does what we see with a microscope correspond to structures really present in the sample?

---

Hacking:

We can distinguish real features from artefacts.

• Certain types of features present no matter what the sample -> due to the 'scope.
• Certain features observed in a sample using very different kinds of 'scopes -> due to real features of the sample interacting with different 'scopes

---

What a microscope gives:
a MAP of interactions between the specimen and the imaging radiation.

Hacking thinks this is good reason for believing certain features of the specimen exist.

But, we may have a hard time getting completely true information about these features.

---

"Entity Realism"

• Believe the theory identifies really-existing entities.
• Not sure that all the claims the theory makes about these entities are true.

---

An example: the mite.

• Can be seen unaided.
• Certain features (like legs) only seen with aid of 'scope

How to interpret "leg removal" experiments?

Am I forced into some kind of realism?

---

Phil 160 home