To clarify the ground of Realism and Anti-Realism, because some clarity on the claims I’m making can be substantiated even within a typical belief in the superiority of realism over non-realist approaches.
Hilary Putnam proposes “…a realist (with respect to a given theory or discourse) holds that 1) the sentences of that theory are true or false; and 2) that what makes them true or false is something external – that is to say, it is not (in general) our sense data, actual or potential, or the structure of our minds, or our language etc…” (and still later) “ that the theories accepted in a mature science are typically approximately true, that the same term can refer to the same thing even when it occurs in different theories – these viewed by the realist … As part of any adequate scientific description of science and it’s relations to its objects…” This is quoted not to define realism but rather to show that truth must play a central role in the construction of a realist position. More than that it also it seems to me to highlight what it is to hold a realist understanding of theory and the real world. Which is to emphasize the external and evidence. Consequently a minimal proposition that describes a realism, that is to say a scientific realism is as follows: “…Science aims to give us, in it’s theories, a literally true story of what the worlds is like: and the acceptance of a scientific theory involves the belief that it is true…”
This is as I said above is deliberately minimal - a basic statement would argue that science tells a true story, the more complex one states that it merely intends to do so, but either way the central point is ‘truth’. The philosopher who I borrowed the definition from makes great play of the importance of ‘literally’ which he states rules out positions that suggest that science is true if ‘properly understood’ but literally that the statements can appear to be false or meaningless. We are of course dealing with epistemology here in that for a realist – what guides the acceptance of a theory is a belief in its truth. But this is not to suggest that anyone must take such a position but rather that they could. Finally (sic) then – within a scientific realist position it is necessary to recognize that an acceptance that a theory is probably correct means that the theory is probably true. In other words belief can come in degrees along with the consequent understanding a degree of belief that a theory is true. Which is not to suggest that this is the same thing as saying that something is approximately true.
Consequently : If realism is the position that the construction of a scientific theory aims to give a literally true story of what the world is like and that the acceptance of such a theory must include the belief that it is true — why do I not like this…? Because anti-realism is a more rational and intelligent position - anti-realism is a perspective that proposes that the intention of science and theory can work well without giving a literally true story, and that accepting a theory can properly involve something completely other than belief that it is true. [This for example I can think of myself as both a Marxist, Deleuzian (and sometime ex-SI) without regarding the theoretical contradictions as a problem – if I thought that any of these were realisms this would be a problem…] An anti-realist does not believe that to propose a theory is to specify that it is true, rather what is done is to claim that it has specific values which make it useful. These values will probably mean that it cannot be said to be true – but they may well be empirical adequate. The reason why ‘literally true’ is important is that within a realism the argument that a given theory represents the truth is often made – for example ‘the second law of thermodynamics’ – and within realism the statements that support the second law of thermodynamics are also considered to be literally true and are ‘literally’ a true representation of reality, until the theoretical proposition is proved to be incorrect. An anti-realist however maintains that whilst a theoretical statement can and probably should be understood literally, a theory need not be true to be useful and adequate. [This is not to accept a positivist approach – in which theoretical propositions and concepts only have meaning in their connections with what is observable. Which is to imagine that two alternative theories can say the same thing though they contradict each other….enough]. So what I accept as an adequate constructivist position – which is a reasonable anti-realist position in that it does not require a belief that a theory should of necessity be attempting to represent the truth and/or the real.. [still using science…]: “…Science aims to give us theories which are empirically adequate, and the acceptance of a theory involves it’s acceptance only insofar as the theory is empirically adequate…”
Something being empirically adequate implies that the theoretical model being proposed must relate to the actual things being described, and that the things the theory implies must be observably true…. I could go on: but let me pause here….
It is obvious then that discourse is not considered separate from the world being described – discourse in this sense would also be understood as a matheme, if it makes a claim to be theoretically adequate it must relate to the actual objects being described. If empirical examples are raised from physics, the human social and so on – there is no performative contradiction for on an everyday basis ‘reality’ is merely a convention adopted because of our specific circumstances. The theoretical model that is adopted calls this ‘reality’ into question at the same time as does our everyday lived practice. Anti-realism – does not reduce the world to thoughts and discourse, any-more than a realism does in its claims for mathematics being a realism - what it does is question whether a realist model which claims that a theoretical proposition represents the truth/real of the world is either necessary or an accurate way to understand the world. An anti-realist, a constructivist position precisely recognizes that an act of torturing a human or non-human – takes place and must be understood as such – but that the discursive act of ‘talking about torture’ needs to addressed and understood as well. Freud’s insight into phantasy always needs to be born in mind here – for example – [A young girl who cut her own tendons in objection to being forced to marry someone last week – was being offered support whether or not the justification was true or false.]. The underlying point being that no examples work to support a realism rather than an anti-realism constructivist position, because of the important misassumption that an anti-realism is not addressing the observable and everyday world.
One might argue that realism is probabilistic rather than truth based, certainly but not yet…