I don’t think there are empirical truths. The idea that there are such truths is a hangover from positivism and empiricism, now discredited epistemologies, even though many social scientists seem unaware of this.
Also, from my viewpoint one really needs to distinguish between three kinds of knowledge: biological knowledge, mental knowledge, and cultural knowledge. Biological knowledge and mental knowledge are “subjective” in character, in the precise sense that they’re not sharable. In saying that they’re subjective, I am not saying that they are not real, and I am also not saying that they are not important, and I am also not saying that we cannot have objective knowledge about such subjective knowledge. Also, biological and mental subjective knowledge are very important because they are the immediate precursors of our actions.
Nevertheless, the only knowledge that is “objective” is cultural knowledge. It is “objective” when it is both sharable among humans and also refutable through criticisms, tests, and evaluations. Let’s now focus specifically on the part of culture called linguistic assertions about the real world. These assert “objective information” provided that they’re sharable. Objective Knowledge is a subset of this information and is comprised of those assertions, knowledge claims, that have survived our criticism, tests, and evaluations (assuming, of course, that they remain sharable and refutable).
I don’t think there is a school of thought that is a philosophical school of thought that is constructivist about some forms of knowledge and objectivist (in my sense) about other forms of knowledge; but I do think there are many people who believe in this. They accept that the methods of knowledge claim evaluation developed in scientific practice in certain scientific fields, and in certain other, practical, areas of life, provide a basis for selecting among false and true knowledge claims. But they do not accept that the same or similar knowledge claim evaluation practices provide a basis for selecting among competing knowledge claims in the social sciences, or in the areas of morals and ethics, on in ontology and epistemology. In these areas, they simply believe that one person’s knowledge claims are as good another’s, and they are basically relativists in their approach.
The relativism of the constructivists is founded on the idea that our beliefs and knowledge claims are determined by our biological makeup (biological constructivism), or that these are determined by our cultural background and experiences (social constructivism), or both in combination, and also that because they are so determined they cannot correspond to the external world (i.e.cannot be true). Constructivism also holds that since our processes of critical evaluation also rely on knowledge; they too are determined by these same factors and carry a built-in bias that render them ineffective in eliminating error and selecting true alternatives among our knowledge claims.
Having outlined the basis of constructivist relativism above, we can ask whether those who accept constructivism in the social sciences, and in morals, ethics, ontology and epistemology, but reject it in “the Natural Sciences” and certain practical areas are being consistent. That is, there is nothing in the constructivist argument that suggests any differential application depending on the area of inquiry. According to constructivism, all of our categories, all of our knowledge claims, everything we think is determined by external and subjective factors and there is absolutely no reason to believe that knowledge claims arising from creatures subject to these factors would or should correspond to reality, or that the evaluation practices of such creatures would work to eliminate errors and arrive at formulations that are close to the truth.
So, for consistent constructivists, there should be no distinctions between areas of inquiry regarding the possibility of attaining objective knowledge, and so from a consistent constructivist point of view, one can’t pick and choose among areas and say, I’ll accept constructivism here but not there. To make such a choice is, in fact, to question the validity of constructivism, unless one can give a special reason why the fact that we construct our knowledge claims under biological and social constraints makes correspondence with reality impossible in some areas of inquiry, but not in others. However, I’ve never seen any arguments that have shown such impossibility. So, it seems to me that Discretionary Constructivism has no basis in reasonable argument, but, in the end, is a kind of fideism saying that we ought to have faith that we can develop objective knowledge in the Natural Sciences, but not in other areas of inquiry.