Friday, November 19, 2010

There's Sensation and then there's Sensation

[This is perhaps germane to yesterday's exchange with Gary re: Associationism vs Computationalism.]

It seems to me that "sensation" is used ambiguously in the EP literature.  Sometimes (when discussing vision) "sensation" means something like retinal stimulation (as Andrew claims in his post here).  Let's call this sensation-rs.  Sometimes, however, "sensation" means something like an observation report of the sort discussed by the logical positivists earlier in the century.*  Let's call this sensation-or.  Very roughly, at least part of the difference is that the first does not seem to involve conscious mental experience, where the latter does.

So, this means that when one denies that perception is based on sensation, there are (at least) two distinct things one can mean:

1) Visual perception processes sensation-rs.
2) Visual perception processes sensation-or.

Gibson at least seems (to me) to want to reject both claims, but it seems to me that 1) is pretty plausible (it's what cognitivism typically asserts), where 2) is not.

Relatedly, I think that Merleau-Ponty spent some time arguing against 2), but I don't know about 1).

* Reed & Jones, (1978), refer to Agassi, (1966), as a target of their criticism.  Agassi discusses observation reports.

Agassi, J. (1966). Sensationalism. Mind, 75(297), 1.
Reed, E., & Jones, R. (1978). Gibson's Theory of Perception: A Case of Hasty Epistemologizing? Philosophy of Science, 45(4), 519-530.


  1. Whereas Gibson spends a lot of time talking about why he thinks (1) isn't plausible. He has lots of reasons, so you need some too :)

  2. I could not possible enter all the evidence for 1) on this or any blog!

  3. I was just commenting that just because it seems to you (1) is plausible doesn't help, given there's reason to be sceptical, courtesy of Gibson.

  4. Nah ... Gibson's got nuthin'!

    More seriously, this is just an expository post. I'm not working up to an argument.