It should be noted that while the distinction between Realism and Anti-Realism is a purely intellectual distinction with no practical distinction in how science, or other projects for that matter, are performed – the distinction and favoring of Anti-Realism does have us appreciate the pragmatic essence of science and all human endeavor.
Schopenhauer, in his Essays and Aphorisms writes that though Man is of greater intelligence than the beasts, most humans are non-intellectual in the sense that they utilize whatever intelligence they have only for immediate or long-term satisfaction of desire. Those of higher intellect work on the projects of machinery, aeronautics and the “practical sciences” and even greater minds delve into the mysteries of existence and mind itself (what Schopenhauer calls “metaphysics”) and whether the scientist is performing experiments that discover the nature (the “thing in itself”) of things and what the purpose of science, art and ethics ultimately are.
These parameters provide no (or very-little) change in the respective fields in which they analyze, however, they provide human beings with the foundation of all their pursuits and prevent them from being overwhelmed by hubris and forget the nature of these endeavors. That is, though Philosophy does not change science or art, it does remind the science and artist of the proper utilization and nature of their project (to have us learn in order to improve our lives) and can lead them from acting poorly. Philosophy provides the normative realm which decides how human beings should behave while interacting and learning about the descriptive one. Science cannot tell scientists whether developing nuclear weapons is a proper use of their intelligence and knowledge but philosophy (specifically ethics) can.
The exact knowledge we have of the “metaphysical realm” is by the nature of us inhabiting a physical plane (we perceive perceptions, which is our “physics” rather than have access to the thing-in-itself) incredibly limited. However, it is this skepticism of the physical plane being with certainty the metaphysical one, and what the metaphysical consists of that allows humans to be reminded of the aims of their goals – the relinquishment of pain and enrichment of experience. For just as all knowledge is centered on the structure of our minds, so it is that all endeavors and efforts should be structured on what our minds and lives should be. For nothing else is of importance (practically or phenomenally) save the mental states of sentient beings. Because of the egotistical dimension of human beings, this knowledge is self-evident when it comes to one’s own mental states (or is it? For often we run after imagined pleasures when if we really were wise and cared for ourselves we wouldn’t place our happiness in imagined and exterior things but in our own wisdom and virtue) but philosophy and art remind us of the sufferings (if other minds truly exist) of our fellow creatures plighted to exist.