Friday, March 6, 2015

Response to one more comment
In 1976, when I delivered the John Locke Lectures at Oxford, I often spent time with Peter Strawson, and one day at lunch he made a remark I have never been able to forget. He said, "Surely half the pleasure of life is sardonic comment on the passing show".  This blog is devoted to comments, not all of them sardonic, on the passing philosophical show.
Hilary Putnam

 In his comment, Stanislaw Jedrczak thinks that the problems in philosophy of mathematics that I have been talking about in recent posts are due to what he calls “the ambiguity of the existential quantifier”. But ambiguity is a semantical notion, and many – probably a large majority – of philosophers of mathematics deny that “exists” is  ambiguous. It is precisely to avoid problematic semantical claims that I say that potentialism is a rational reconstruction of certain uses of “exist”, rather than a meaning analysis.


Thursday, March 5, 2015

Response to a Comment by Ned Block
In 1976, when I delivered the John Locke Lectures at Oxford, I often spent time with Peter Strawson, and one day at lunch he made a remark I have never been able to forget. He said, "Surely half the pleasure of life is sardonic comment on the passing show".  This blog is devoted to comments, not all of them sardonic, on the passing philosophical show.
Hilary Putnam

Ned Block writes:

 “I think what Sinha showed is that there is a critical period for object-perception. [Ned is referring to my post “Perceptual Transparency and Sinha’s Observations” 1/20/15] He did not show that we have to learn cross-modal connections. There is a ton of data showing that human-babies have built-in cross modal connections at birth. Human babies will turn toward a sound at birth. And human babies prefer to look at a picture of the pacifier they have in their mouth. Also babies imitate facial expressions.” [you can find a video by searching under “Neonate Imitation”]

Ned is absolutely right. I did not know about the critical period. Here is some material on that from the National Institutes of Health:

“This idea of a developmental critical period is largely based on animal studies performed during the 1960s. It’s an influential idea which many researchers use as a basis to design and interpret experiments and many doctors use to make treatment decisions.
Nonetheless, there have been a few rare cases of blind patients who gained sight later in life and learned to recognize some objects. Furthermore, children born blind with cataracts but who had gained sight from surgery a few months after birth eventually learned to recognize most objects. These cases suggest that our brains may be able to learn to see regardless of whether we have vision problems during the critical period.
Every child Project Prakash treats provides one more reason to think that the brain is more flexible than we once thought. So far, the project has treated 200 children, many of whom are older than six years of age. Nine of "the children have been described in scientific journal articles. The average age of these children was 13 years old, ranging from 7 to 24.
Although they do not have perfect vision, all of them have learned to recognize most objects and can rely on their vision to work and play like people who grew up with normal vision. These results support the idea that our brains can learn to recognize objects after the critical period.”

How does this information affect the case I have been making in these posts? That case is directed against the idea that visual experiences are intrinsically transparent, as Tye has claimed. But the Sinha-Held observations as well as Held’s experiments with kittens in the 1960s show that, regardless of whether it be because visual-haptic connections have to be learned (as I thought) or because they have to be activated during a critical period, as is now believed, they are not universally present – not in the case in which that activation fails to occur.  Nor is it the case that in the first hours after sight is restored, the visual objects are experienced as of “external” objects. To quote again [see my post “More on Transparency” 2/2/15] from the description given by Ostrovsky et al (who examined the children in India immediately afer they received the corneal implants)—
“they pointed to regions of different hues and luminances as distinct objects. This approach greatly oversegmented the images and partitioned them into meaningless regions, which would be unstable across different views and uninformative regarding object identity”.

The visual experiences of those children at those times weren’t  “transparent” to them. Afortiori, transparency is not an intrinsic property of visual experiences. I added that the visual-haptic connections are “quickly learned”, and I would now say, “quickly activated”, but my point is unaffected: “transparency” is not an intrinsic feature of visual experience.
Response to a Comment
In 1976, when I delivered the John Locke Lectures at Oxford, I often spent time with Peter Strawson, and one day at lunch he made a remark I have never been able to forget. He said, "Surely half the pleasure of life is sardonic comment on the passing show".  This blog is devoted to comments, not all of them sardonic, on the passing philosophical show.
Hilary Putnam

Tristan Haze writes:

 “Thanks for making this post. [Haze is referring to "Rational Reconstruction" 2/18/15] I'm interested in your notion of rational reconstruction but am bothered by something.

I understand and see the usefulness of the idea of a rational reconstruction as a paradox-free way of construing some problematic discourse. And I understand this as something like giving a new but importantly related meaning to that discourse.

But then when you mention the logical positivists/empiricists and say (approvingly as far as I can tell) that for them a rational reconstruction was 'a proposal to *give* a certain predicate an interpretation that exhibits the rationality of certain uses of that expression', this, naturally interpreted, seems to be in tension with the understanding of rational reconstruction as characterized in the last paragraph of this comment.

The tension is: if a rational construction is not intended to be descriptive of the meaning of some discourse as it already was before the rational reconstruction, then how can it exhibit the rationality of any of it? At best, it exhibits a way of changing one's practise in order to *become* rational. Or am I missing something?” 

Response:  Tristan, you are absolutely right. Instead of saying “a proposal to give a certain predicate an interpretation that exhibits the rationality of certain uses of that expression”, I should have said “a proposal to give a certain expression an interpretation that makes certain uses of that expression that are important to us rationally justifiable”.

Thanks for catching me up on this.