Rainbow as Public Hallucinations

From Bas C van Fraassen Scientific Representation: Paradoxes of Perspective

p. 98 ‘The ‘window into the invisible world’ metaphor has dominated modern philosophical thinking about science as much as the «mirror of nature» metaphor dominated modern epistemology and metaphysics. It will serve us better to dislodge or at least weaken its grip on philosophical discourses, and to think of experimentation in terms of a literal enlargement of the observable world, by the creation of new observable phenomena, rather than a metaphorical extension of our senses».

p. 102-103 “Consider the rainbow. We realize pretty soon that there is no real material shining arch standing above the earth, although at first it looks that way. As a second guess we might think that certain parts of the clouds or haze are colored. But that cannot be maintained because if we move, we see the rainbow in a different location on the cloud or haze background.

In fact, we realize then that our usual way of speaking involves us in falsehood. I see a rainbow and you say you see it too. See what too? How can you be seeing the rainbow I see, when yours is located in a different place? Nor are they simply in a different place in our respective visual fields, in the way clouds are. For if that were so, we would see the colors ‘attached’ to the same part of the cloud, modulo parallax. If on the other hand I say there are two rainbows, and you agree, we are not even counting the same things. In fact, we are not counting things at all.

But thirdly, we are not hallucinating. Hallucinations are private, subjective. These rainbow observations are like hallucinations, in that they are not real things. But they are unlike hallucinations because they are public. Nature creates public hallucinations. So public, in fact, that the camera captures them as well! The observations are scientifically significant in part because they can also be made indirectly, so to speak, with the camera as instrument”.

Representation Of, Representation As

p. 19 “Socrates’ thought experiment … has a quite contemporary ring, if we replace gods (as it usual now) with mad scientists.”

p. 19 Quote from Cratylus (Socrates talks to Cratylus). “Let us suppose the existence of two objects. One of them shall be Cratylus, and the other the image of Cratylus, and we will suppose, further, that some god makes not only a representation such as a painter would make of your outward form and color, but also creates an inward organization like yours, having the same warmth and softness, and into this infuses motion, and soul, and mind, such as you have, and in a word copies all your quantities, and places them by you in another form. Would you say this was Cratylus and the image of Cratylus, or that there were two Cratyluses?”

p. 22 “Look back now at Socrates, Cratylus, and the god they imagine. Did the god make an image of Cratylus or did he not make a representation of anything, but a clone? That depends. Cratylus was too nasty in his response. Did this god go on to display what he made to the Olympic throng as a perfect image of Greek manhood? Or did he display it as an example his prowess at creature-making? Or did he do neither, but press the replica into personal service, since he couldn’t have Cratylus himself?”

On Mathematical Modeling

p. 40 Of course the story is apocryphal, that a professional gambler funded a mathematician to analyze horse-racing, and was thoroughly unhappy with the report that began “Let each horse be a perfect sphere, rolling along a Euclidean straight line …”. But is that so far from real examples of mathematical modeling?’

Self-ascription and “Perfect Model Model”

p. 45 “Agreed, we cannot demonstrate that in principle, as a matter of logic, mathematical modeling must inevitably be a distortion of what is modeled, although models actually constructed cannot have perfection reachable in principle. But on the other hand, the conviction that perfect modeling is possible in principle – what Paul Teller calls the “perfect model model” – does not have an a priori justification either!”

p. 83 “Suppose now that science gives us a model which putatively represents the world in full detail. Suppose even we believe that this is so. Suppose we regard ourselves as knowing that it is so. Then still, before we can go on to use that model, to make predictions and build bridges, we must locate ourselves with respect to that model. So apparently we need to have something in addition to what science has given us here. The extra is the self-ascription of location.”

p. 83 “Have we now landed in a dilemma for our view of science as paradigmatically objective? If we say that the self-ascription is a simple, objective statement of fact, then science is inevitably doomed to be objectively incomplete. If instead we say it is something irreducibly subjective, then we have also admitted a limit to objectivity, we have let subjectivity into science.”

Weyl on mathematics vs. reality

p. 208 “Herman Weyl expressed the fundamental insight as follows in 1934:

‘A science can never determine its subject-matter expect up to isomorphic representation. The idea of isomorphism indicates the self-understood, insurmountable barrier of knowledge. […T]oward the “nature” of its objects science maintains complete indifference.’ (Weyl 1934:19)

The initial assertion is clearly based on two basic convictions:

o  that scientific representation is mathematical, and
o  that in mathematics no distinction cuts across structural sameness.”

p. 209 “Weyl illustrates this with the example of a color space and an isomorphic geometric object. … The color space is a region on the projective plane. If we can nevertheless distinguish the one from the other, or from other attribute spaces with that structure, doesn’t that mean that we can know more that what science, so conceived, can deliver? Weyl accompanies his point about this limitation with an immediate characterization of the ‘something else’ which is then left un-represented.

‘This – for example what distinguish the colors from the point of the projective plane – one can only know in immediate alive intuition.’ (Ibid.)”

p. 210 “We seem to be left with four equally unpalatable alternatives:

o  that either the point about isomorphism and mathematics is mistaken, or

o  that scientific representation is not at bottom mathematical representation alone, or

o  that science is necessarily incomplete in a way we can know it to be incomplete, or

o  that those apparent differences to us, cutting across isomorphism, are illusory.

In his comment about immediate alive intuition, Weyl appears to opt for the second, or perhaps the third, alternative. But on the either of this, we face a perplexing epistemological question: Is there something that I could know to be the case, and which is not expressed by a proposition that could be part of some scientific theory?”

Bad Theory as a Bad Tragedy

p. 266 ‘Aristotle himself seems to see the parallelism very well. When in the Physics he comes to what he considers a bad theory (the theory of evolution by natural selection and chance variation, as it happens!) he make fun of it. It does not meet his standard for scientific knowledge, for it does not “deal adequately with the ‘why’ … in terms of each type of explanatory factor.” And he emphasizes that again in Metaphysics: “But the phenomena show that nature is not a series of episodes, like a bad tragedy.”‘

Does the World exist?

From The Empirical Stance (The Terry Lectures Series) by van Fraassen:

Lecture 1. Against Analytic Metaphysics

3. Does the World Exist?

p. 5 “Doesn’t the answer seem obvious to us? We are all part of this earthly ecosystem, which is part of the solar system, and that is part of the Milky Way galaxy, and so forth. Surely this progression has an end, a final term? And that is what we all agree in calling the world.

Oh, Oh … The moment we have made this ‘obvious’ answer explicit, we are reminded of famous proofs of the existence of God. Those demonstrations tend to prove the existence of something and end with the words ‘and that we all agree in calling God’. But those arguments we now all agree in calling unsound.”

p. 6 “Whether the world exists is in fact a traditional question of metaphysics. Indeed, it encompasses three questions: What is a world? Does the world exist? Are there perhaps other worlds as well?”

«In every century we must reinterpret ourselves to ourselves. We do not come in our century with a tabula rasa. We must interpret what we find ourselves to be, with an eye to what we have been and to what we could be and can be. That is the perennial, ever-recurring task, ever new.»

God is Dead

“Let us begin with a statement that I am sure you must have heard before:

God is dead.

You are right if you take it that I am serious about this. But what do I mean? When Pascal died, a scrap of paper was found in the lining of his coat. On it was written ” The God of Abraham, Isaac and Jacob, not the God of the philosophers.” Pascal was a contemporary of Descartes in the seventeenth century, and the God who appears in Descartes’ Meditations on First Philosophy was the paradigmatic philosophers’ God. He is of course omniscient, omnipotent, and omni-benevolent, and he is designed precisely so as to guarantee that everything that Descartes says is true. So Pascal had a very good example near at hand. Here is what I mean when I say that God is dead:

The God of the philosophers is dead.

This God is dead because he is a creature of metaphysics – that type of metaphysics – and metaphysics is dead.”