Believing a reality exists in the absence of experience of that reality is idolatry; reifying a purely abstract concept (i.e. a hypothetical assumption). Idolatry entails accepting as ‘true’ or ‘real’ something one has not experienced, hence something that is in direct contrast to one’s actual knowledge. Idolatry, then, not only involves granting ‘truth’ to a mere conjecture, but granting more trust to an external authority (e.g. orthodoxy, dogma, consensus, etc.) than to the evidence of one’s own actual experience.
Contemporary cosmology qualifies as idolatry in the above sense in that it begins by accepting as true the mere hypothesis, ‘reality is not what it appears to be’ (i.e. what we experience as reality, is not reality itself). In contrast, Zen cosmology begins by recognizing the truism, ‘what we experience as reality is the only reality we will ever experience’ (i.e. that ‘reality is what is experienced’ is self-evident). Thus, Zen not only refuses to accept notions about reality that are contrary to our actual experience of reality, it denigrates the practice of purely speculative conceptualization, which it recognizes as not merely futile, but harmful.
Excerpt from, Zen Cosmology: Dogen’s Contribution to the Search for a New Worldview pp.96-97