Handling Truth: Navigating the Riptides of Rhetoric, Religion, Reason, and Research (2012) by William Melvin Gardner.

We know no higher experience than human experience, no higher understanding than human understanding, and no truth higher than that formed within the confines of, and expressed with, language. We know only the truth of the four sovereign domains of truth.

In the oldest domain, RHETORICA, statements are advanced or discredited by the process of persuasion and debate, or rhetoric. In Rhetorica, truth always remains a matter of opinion. In the second domain, MYSTICA, truths are articles of faith or beliefs, arising from and tested by spiritual revelation, prophecy, sacred texts, personal enlightenment, or other mystical processes. In LOGICA, truths are inferences or proofs that have been validated with the methods of logic. The fourth domain is EMPIRICA, and its truths are empirical findings, confirmed and documented by research.