Q&A: Carnap’s Blind-Man Parable Trips Itself Up
Carnap’s Blind-Man Parable Trips Itself Up
Question
Greetings and blessings, Rabbi, good evening. At the end of the lecture I wanted to point out a genuinely contradictory argument in Carnap’s doctrine. I wasn’t clear, so I said I’d present it more clearly.
Carnap attacked the approach that there are concepts we cannot grasp, and yet they do exist.
He presented the challenge to his view: perhaps there *is an omniscient being that can give us information about that concept (which would mean it exists even without our confirmation), and then the concept does exist*, even though we have no ability to absorb it in our consciousness. (Exactly like a blind person whose sense of sight does not work, but an outside person who can see can point to the existence of objects.)
Afterward he tried to refute that challenge by saying that in the parable of the blind person, the kind of information given to the blind person can receive support from other senses, such as touch. So it is understandable why the blind person can accept his friend’s visual system as something valid, because he succeeded in confirming it once.
But here in our case, there is no possibility of adopting a metaphysical concept on any perceptual scale. Therefore, even if such a being were to tell us about some new concept like that, we could not accept it.
My criticism is that Carnap treats science as something acceptable; he does this in a distinctly rationalist way (as the Rabbi nicely elaborated in the session). If so, then indeed a rationalist concept has been introduced for Carnap.
So according to his own view, why shouldn’t we accept the entire rationalist (metaphysical) arsenal, just as the blind person will come to trust sighted people once it has been confirmed a single time (through his sense of touch)? From that point onward it is an acceptable concept.
It may be that I didn’t write this clearly enough, but in principle that is the contradiction I wanted to point out. (It is not only an a priori contradiction in the doctrine of logical positivism, but a contradiction emerging from his own reflections, from within his own method) with the blind-man parable.
Answer
I do not understand the argument. Do you mean to argue against him on the basis of his trust in science? I spoke about that. What is there in the discussion about the blind person that strengthens that claim? It is just another example of using science.
Discussion on Answer
And by the way, what I wrote is against the background of these words of his:
"Where there is no question, even an omniscient being would not be able to provide an answer. Now the opponent may say: *Just as the sighted person can convey new knowledge to the blind person, so a higher being could convey metaphysical knowledge to us*…..
*Here we must consider the meaning of ‘new knowledge.’ It is indeed conceivable that we might encounter creatures who tell us about a new sense. If these beings prove Fermat’s Last Theorem to us, invent a new physical device, or discover a law of nature that until now was unknown, our knowledge will grow with their help. This we can examine, just as the blind person can understand and examine the whole of physics (and consequently any claim given to him by those who can see).*"
To be honest, there really is nothing new here; this is what the Rabbi said.
It is simply pointing out the absurdity of his method, from within his own article. (Because if he believes in science, then there is already *meaning* to rationalist data. Accordingly, the category of rationalist meaning has been opened up, so it is not nonsense. And the same would apply to all metaphysics, etc.).