https://plato.stanford.edu/entries/realism/The question of the nature and plausibility of realism arises with respect to a large number of subject matters, including ethics, aesthetics, causation, modality, science, mathematics, semantics, and the everyday world of macroscopic material objects and their properties. Although it would be possible to accept (or reject) realism across the board, it is more common for philosophers to be selectively realist or non-realist about various topics: thus it would be perfectly possible to be a realist about the everyday world of macroscopic objects and their properties, but a non-realist about aesthetic and moral value. In addition, it is misleading to think that there is a straightforward and clear-cut choice between being a realist and a non-realist about a particular subject matter. Rather, one can be more-or-less realist about a particular subject matter. Also, there are many different forms that realism and non-realism can take
This seems to be something new to me. There wasn't much talk about it (that I encountered, at least) when I was studying Philosophy at George Mason University in the late 1980s. However, it has peaked my interest after seeing some of Veritas Aequitas' posts. And I'd like to learn more about this new thing.
Can and would someone help me understand it better?
I guess, for starter questions:
What is anti-realism?