Fred Dretske

(1932 - 2013)

This chapter separates cognition from perception by distinguishing between the percept—the product of pure perception which is conceptually untainted by cognitive ingredients—and a larger and more inclusive experience that is conceptually affected. It then criticizes Siegel’s view that higher-level properties are included in the content of perceptual experience, and the view that cognition affects the percept. The chapter uses a thought experiment, the ‘Goldilocks test’, to isolate cognitively unspoiled sensory core of perceptual experience. Application of the test to the perception of kinds yields the result that subjects who possess different concepts (expert and novice viewers) have the same percept. The chapter also applies the Goldilocks test to other visual cases, such as reversible figures.

It is a traditional empiricist doctrine that natural laws are universal truths. In order to overcome the obvious difficulties with this equation most empiricists qualify it by proposing to equate laws with universal truths that play a certain role, or have a certain function, within the larger scientific enterprise. This view is examined in detail and rejected; it fails to account for a variety of features that laws are acknowledged to have. An alternative view is advanced in which laws are expressed by singular statements of fact describing the relationship between universal properties and magnitudes.

A certain dilemma is inherent in relational accounts of space and time. If any objects endure through change, then temporal elements other than relations are required to describe them. If, on the other hand, no objects endure through change, no permanent reference system is available in terms of which to define the "same place" at different times. An argument which, by exploiting this latter difficulty, attempts to show that "objects with some endurance through time" must be accepted as fundamental is examined and found inconclusive. A sketch is then given of an alternative scheme which does allow the relevant spatial comparisons, but which does not countenance the reidentification of particulars. The discussion is intended to show that the relationist can, as indeed he must, deny the second horn of this delemma.

Peter Baumann and Nicholas Shackel defend me against a serious criticism by Christoph Jäger. They argue that my account of information is consistent with my denial of closure for knowledge. Information isn’t closed under known entailment either. I think that, technically speaking, they are right. But the way they are right doesn’t help me much in my effort to answer the skeptic. I describe a way in which information, like knowledge, fails to be closed in a way that makes an information-based account of knowledge an effective tool in answering the skeptic.