A domain is the set of elements upon which some operation is to be performed, such as a mathematical function or mapping. A cognitive domain is some defined level of information processing—a data set or domain of description. It may be operated upon and transformed into a new data set, defining a new cognitive domain. This may then serve as the input to some other level of further operations or processing. The problem of cognitive domains is the dilemma of logical circularity that arises when the output of a cognitive process is recycled as its input. This occurs, for example, when the physical world that appears in conscious experience is presupposed in order to explain the brain’s very construction of this appearance in consciousness. The output of mental processing is taken to be its input; a domain of description is recycled as its own rationale. Attempts to explain how the mind builds its picture of the external world typically begin with the very picture of the world they attempt to explain. The whole account of cognition leads up to and includes the physicist’s constructed version of reality, which is then assumed to be the starting point of the story! This is a general epistemic dilemma, which applies not only to perception but to every form of cognitive activity, including science. The scientific story must begin somewhere—with basic theoretical constructs it presumes to be real. These are products of the scientific process (for example, models) yet are recycled as realities in the causal story leading up to the existence of scientists and the scientific story. First-order science cannot come to terms with this shift in domains of description and the consequent circularity. Schopenhauer likened such a bootstrapping operation to the legendary Baron von Munchausen, who—in order to cross the river without drowning—lifted himself and his horse out of the water by pulling up on his own pate!