realist, anti realist. Do science tell us about the world?

Thus they [scientists] speak as if there are unobservable entities with causal powers. But when they do this, what they're really doing is simply saying something about how their theory or "model" fits together - and not saying anything about how (unobservable) reality fits together.

quantum physics confirms something that many philosophers have suspected for centuries. In short, human beings don't actually know the cosmos as it is in itself: it is, as d'Espagnat has called it, a 'veiled reality'. Rather, we only know the world as it comes to us. He has said that observing the world is rather like looking at a rainbow: it looks real, though we know the way it appears to us depends entirely on our location and perceptions.

Immanuel Kant, the great Enlightenment philosopher, formulated a similar suggestion. He argued that we can only get to grips with the world of phenomena, and that the world of noumena - things as they are in themselves - remain permanently beyond our reach. Where d'Espagnat differs from Kant is that he doesn't doubt that the world beyond us really exists. Rather, it's 'just' a mystery to us. Hence he can be called a 'transcendental realist', rather than Kant, who is known as a 'transcendental idealist'. So, d'Espagnat's is not a 'brain in a vat' scenario. When d'Espagnat kicks a stone, and feels the pain, he concludes that something real is resisting the forward motion of his boot. There is a ground of things but it lies beyond our concepts. Quantum physics reminds us of this, and perhaps provides us with a sidelong glimpse of it.

Realism: We have very good reason to believe that the unobservable entities postulated by well-confirmed theories exist.

"Constructive empiricism": We have no good reason to suppose that such entities exist. The evidence which supports scientific theories supports only the claim that such theories are "empirically adequate" - that what they say about observable entities is true. We have no reason to suppose that what they say about unobservable entities is true.

Instrumentalism: This is a thesis about the meaning of "theoretical" terms (i.e. terms which appear to refer to unobservable entities). Instrumentalists claim that such terms don't really refer to any such entities. A theory employing theoretical terms is really only "about" the observable world: what makes the theory true is the observable facts being the way the theory says they are.

From that paper provided .

This is rather similar to the instrumentalist view, is it not? What we see are dials indicating various measurements - we are not seeing 'something that causes the dials to move', or if we are, it is impossible to surmise what that 'something' is.

I think the realist view has been under threat from quantum mechanics from the outset. The question as to whether subatomic particles exist is still contentious. For example electrons can be seen as waves in some contexts, and particles in others. Even when they are understood as particles, they are understood to be completely indistinguishable one from another. This lead Richard Feynmann to consider whether there is really only one electron in the Universe.

Bernard D'espagnet, who won the Templeton Prize in 2009, believes that

Source

TuringEquivalent,

If the handout is any indication of the course, I think non-realist positions are being a little misrepresented. The undergraduate Philosophy of Science course I took had the same problem.

The misrepresentation largely derives from lack of distinction being made about the role of language in relation to the various positions. For example:
Non-realist positions do not necessarily disagree with the above statement. What they disagree with is the realist notion that language and conceptual structures correspond to the "unobservable" entities that exist i.e. they reject notion language somehow directly maps onto reality. This matter is omitted in the realist position, as presented in the handout.

Note how the realist definition is about what exists, while the other positions are presented as being about what is "said" about what exists.
The first sentence should really say, "We have no good reason to suppose that such entities exist as described through linguistic conventions."

Also constructive empiricism, is about what can be said; not what is. It is not that the entities do not exist, instead what is said about the entities only have "empirically adequate" confirmation.

Let's look what the handout says about Instrumentalism:
Note, it says "terms don't really refer to any such entities", which is a statement about the relationship between language and reality. Instrumentalists generally reject correspondence theories of truth and meaning. An instrumentalist might say, "terms represent the entities" in various ways, such as the wave-particle description represents the entities that behave in that way. But that doesn't mean the description is the entity.

The second statement in bold about instrumentalist position is partially correct, however realism has slightly bastardized the position by positing observable and unobservable realms. For an instrumentalist the behavior of electrons is observable, i.e. how it reacts to other particles under certain conditions, such as giving off radiation (light, heat ...etc) suggest something exists, even if the entity itself is not directly observable.

Long head...We have a language to map reality, and that is math... Language works better for moral forms which is a way of conceiving of spiritual/moral reality... Most of our reality is all meaning without being... You cannot throw god on a scale even if you can hang him on a cross... If the thing cannot be produced it cannot be classed, measured, compared or understood...Well that is the world we live in, the world which presents us with our greatest challenges... We are moral beings, and even our lives cannot be conceived of...

Quote:

Instrumentalists generally reject correspondence theories of truth and meaning.

I doubt it. Consider the observable, dog. We have the name 'dog', and we can obviously spot one when we see it.