Realism is the belief that the objective world exists independently of human observers: there are entities and facts out there that exist independently of our minds. It is not a thesis about how the world is; it does not say ‘how things are but only that there is a way that they are’ (Searle 2007). Idealism is an anti-realist position that assumes that reality is essentially mentally constructed. Nothing that exists is independent of the mind.
While these two metaphysical positions may seem like opposite ends of the spectrum there is a good deal of overlap in the way they are applied in modern philosophy. Most realist believe in a mind of sorts and most idealists don’t reject a material world. It is more an emphasis of approach, hence an epistemological concern rather than ontological one. We can represent the realist viewpoint in the following diagram where the ego, or the ‘I’, is located in the centre. The realist looks outward to the material world rather than inward to the mind. Any consideration of the mind, if at all, come through the study of the material.
mind << REALIST >> matl. —> mind
In the second diagram, the idealist however assumes that we can only look out to the material world through the mind. The description of the mind has priority over the material and it is only through the mind that we can come to know the material. The realist takes a third-person perspective whereas the idealist assumes a first-person perspective.
IDEALIST >> mind >> matl.
NLI (nonrepresentational linguistic idealism) assumes the second position, that of the idealist. It assumes that our view of the objective world is essentially through the prism of language. Language is all we have to divide up the material world.
Searle, J. (2007). The construction of social reality (Penguin philosophy). London: Penguin.