The scientific realist maintains that in at least some cases, we have good evidential reasons to accept theories or theoretical claims as true, or approximately true, or on-the-road-to-truth. The scientific antirealist denies this. These attitudes come in degrees... [T]his is a question addressed by epistemology and confirmation theory...

It has become almost de rigueur in quantum foundations literature to misuse the terms "realist," "realistic," "antirealist," and "antirealistic." These terms have a precise meaning in the philosophy of science... that seems to be... unfamiliar to most physicists. ...[T]hey simply toss them around with no attached meaning ...[with] terrible consequences in foundations of quantum theory.

There you have, then, a theoretical physics which is neither the theory of a believer nor that of a nonbeliever, but merely and simply a theory of a physicist; admirably suited to classify the laws studied by the experimenter, it is incapable of opposing any assertion whatever of metaphysics or of religious dogma, and is equally incapable of lending effective support to any such assertion.

A physical theory, like an abstract science, consists of definitions and axioms as first principles, and of propositions, their consequences; but with these differences:—first, That in an abstract science, a definition assigns a name to a class of notions derived originally from observation, but not necessarily corresponding to any existing objects of real phenomena, and an axiom states a mutual relation amongst such notions, or the names denoting them; while in a physical science, a definition states properties common to a class of existing objects, or real phenomena, and a physical axiom states a general law as to the relations of phenomena; and, secondly,—That in an abstract science, the propositions first discovered are the most simple; whilst in a physical theory, the propositions first discovered are in general numerous and complex, being formal laws, the immediate results of observation and experiment, from which the definitions and axioms are subsequently arrived at by a process of reasoning differing from that whereby one proposition is deduced from another in an abstract science, partly in being more complex and difficult, and partly in being to a certain extent tentative, that is to say, involving the trial of conjectural principles, and their acceptance or rejection according as their consequences are found to agree or disagree with the formal laws deduced immediately from observation and experiment.

Scientific realism in classical (i.e. pre-quantum) physics has remained compatible with the naive realism of everyday thinking on the whole; whereas it has proven impossible to find any consistent way to visualize the world underlying quantum theory in terms of our pictures in the everyday world. The general conclusion is that in quantum theory naive realism, although necessary at the level of observations, fails at the microscopic level.

The first question we should face is: What is the aim of a physical theory? To this question diverse answers have been made, but all of them may be reduced to two main principles:
"A physical theory," certain logicians have replied, "has for its object the explanation of a group of laws experimentally established."
"A physical theory," other thinkers have said, "is an abstract system whose aim is to summarize and classify logically a group of experimental laws without claiming to explain these laws...
Now these two questions — Does there exist a material reality distinct from sensible appearances? and What is the nature of reality? — do not have their source in experimental method, which is acquainted only with sensible appearances and can discover nothing beyond them. The resolution of these questions transcends the methods used by physics; it is the object of metaphysics.
Therefore, if the aim of physical theories is to explain experimental laws, theoretical physics is not an autonomous science; it is subordinate to metaphysics...
Now, to make physical theories depend on metaphysics is surely not the way to let them enjoy the privilege of universal consent.

It has generally been assumed that of two opposing systems of philosophy, e. g., realism and idealism, one only can be true and one must be false; and so philosophers have been hopelessly divided on the question, which is the true one.

General relativity is certainly a very beautiful theory, but how does one judge the elegance of physical theories generally?

I propose to answer two questions:—
(1) Is the Theory of Gases a true physical theory as valuable as any other physical theory?
(2) What can we demand from any physical theory?

The idealist tradition, including contemporary phenomenology, has of course admitted subjective points of view as basic and has gone to the opposite length of denying an irreducible objective reality. … I find the idealist solution unacceptable …: objective reality cannot be analyzed or shut out of existence any more than subjective reality can. Even if not everything is something from no point of view, some things are.<p>The deep source of both idealism and its objectifying opposite is the same: a conviction that a single world cannot contain both irreducible points of view and irreducible objective reality — that one of them must be what there really is and the other somehow reducible or dependent on it. This is a very powerful idea. To deny it is in a sense to deny that there is a single world.

The true realist is he who believes in both God and the Devil, and is prepared to attempt, with humility, to sort out some corner of the extraordinary tangle of their works which is our world. He cannot use his feeling alone, he must use his intellect.

Not ordinarily do men achieve this balance of opposites. The idealists are not usually realistic, and the realists are not usually idealistic. The militant are not generally known to be passive, nor the passive to be militant. Seldom are the humble self-assertive, or the self assertive humble. ...truth is found neither in the thesis nor the antithesis, but in an emergent synthesis that reconciles the two.

I'm more of a realist, than a theorist

In the absence of experimental evidence, basic beliefs of theoretical physicists may initially have almost a religious flavor, guided by faith and aesthetics. Fortunately unlike religion, these beliefs soon face the hard test of experiment.