First, I think that true and false are terms we should apply to linguistic networks rather than single statements. Networks are necessary, because single statements generally assume a good deal of background knowledge illuminating the meaning of those statements. If the background knowledge is expressed in language also, we have a network of statements, and it is this network, not the single statement that actually gets tested in evaluation. In cases where we’re using observations to test such a network, observations running contrary to the expectations suggested by the network never logically compel us to falsify any individual statement in the network, but they set a problem of inconsistency for the network, and to solve that problem we have to decide which of its statements must be falsified.
So, second, are there knowledge claim networks that are more or less true? Well, yes and no. More specifically, if the network in question is about reality it must be either true or false. However, among false knowledge claim networks, some may be closer to the truth than others. For example Newton’s Theory of Gravitation is, as far as we now know, false. However, it is closer to the truth than earlier theories about why objects behave as they do in the vicinity of the earth. Also, Einstein never really believed that his own General Theory of Relativity was true, and thought that it would one day be superceded by a better theory. On that day we will view Einstein’s theory as false, but also as closer to the truth than Newton’s Theory.
So, third, now the question arises, how can we compare competing theories in terms of closeness of approach to the truth. Popper developed a theory about this, but Pavel Tichy and David Miller (Popper’s student and later collaborator), both independently showed that Popper’s formal account of closeness of approach to the truth was wrong. Popper never offered an alternative because he thought it wasn’t fundamental to his work to develop a measurement model for this property (the single term for which is “verisimilitude). Others since Popper have continued to try to develop such a measurement model. Currently, the leading researcher in this area is Illka Niiniluoto a Professor at the University of Helsinki. In 2003, I developed a model of my own in the Appendix to Chapter 5 of my book with Mark McElroy, Key Issues in the New Knowledge Management. Of course, such a model amounts to a formal theory of knowledge claim evaluation and must include evaluation criteria. Those were presented and discussed in Chapter 5 of Key Issues . . ., where the criteria were viewed in a more qualitative way as perspectives and where knowledge claim evaluation was viewed as a largely qualitative process compared with the view taken in the Appendix.
Fourth, I don’t think our theories of knowledge claim evaluation are true or false, as are our theories about reality. They are theories alright; and as such they are conjectural. But I think they are normative theories, theories about the ethics of inquiry and knowledge production. And I also think that these theories are about fairly comparing competing theories dealing with reality, so that alternative theories of knowledge claim evaluation are also alternative theories of fair comparison. We can compare these alternative theories of fair comparison, but we need yet another theory to do so, this time one for fairly comparing fair comparison theories of knowledge claim evaluation.
Fifth, this is not an infinite regress situation, however. The reason is that at the level of fairly comparing fair comparison theories of knowledge claim evaluation, we are out of levels. That is, at that level, we can only compare theories of fair comparison using the theories of fair comparison we already have, with the exception that we can think of new theories that would apply at both levels at which there are theories of fair comparison. The reason why it may seem that this is an infinite regress situation, is because some will assume that the theories of fair comparison we select as legitimate at each level must be “justified” before we select them. For those requiring “justification” it will always be possible to ask whether one’s decision to select a theory of fair comparison was justified and that will drive one to a higher level of evaluation. However, if one assumes that justification is unnecessary, and that the fair comparisons will be carried out through criticism only, then the situation changes because the best surviving alternative among theories of fair comparison in the face of criticism, is the best performer at both levels at which theories of fair comparison are compared.
Sixth, all reality is not a human construct, but, I do think that the idea of truth is either a human construct or at least one of intelligent creatures having descriptive languages including humans and intelligent creatures evolving elsewhere in the multiverse. In my view, truth is correspondence between what our linguistic constructs assert about reality and reality itself. So we can’t talk about such a correspondence without descriptive languages, and such languages are created by societies of intelligent agents like humans.
Seventh, I don’t believe this view represents a paradigm shift for realists like me, since, as Popper showed time and time again, a belief in realism isn’t in contradiction with the idea that we humans construct our knowledge. Realism, instead, contradicts the view that because we construct our knowledge, it cannot be true or “objective.”