In “Can We Solve the Mind-Body Problem?”, Colin McGinn introduces the idea of a property or theory being “cognitively closed” (350) to an individual. This means there are phenomena and knowledge of phenomena that minds do not have the cognitive ability to comprehend. According to McGinn, “A type of mind M is cognitively closed with respect to a property P (or theory T) if and only if the concept-forming procedures at M’s disposal cannot extend to a grasp of P (or an understanding of T)” (McGinn, 350). This means that a type of mind, M, where M is an human being’s mind, cannot grasp an illogical property, P, or illogical theory, T, because illogical properties and illogical theories, P and T, respectively, exceed the limits of the human mind; the human mind cannot grasp an illogical property or theory. An example of a property being cognitively closed to an individual is the illogical property that can be extracted from the illogical statement that X = ~X. Given that X = ~X is an illogical statement, this means M cannot deduce any property/properties from this statement because M cannot make sense of a logical contradiction. Granted, in some logical systems, contradictions allow for what is called inferential explosion — i.e. everything is derivable from them, generally speaking, knowledge of contradictions is beyond M’s and any other individual’s cognitive capacities. As a result, the illogical property/properties that can be abstracted from logical contradiction of X = ~X is a property that is cognitively closed to M and any other individual. However, it is debatable whether or not illogical properties exist, and thus, whether or not they are cognitively closed to the human mind.
An example of a property or feature of the world that is cognitively open to human beings but cognitively closed to some other non-human animal is: rationality – as understood in the Aristotelian tradition. In the Aristotelian tradition, human beings are defined as rational animals; the capacity to critically think and reason is what separates human beings from other non-human animals. Thus, as understood in the Aristotelian tradition, rationality is a property that is cognitively open to human beings but cognitively closed to other non-human animals. Moreover, just because rationality eludes the cognitive capacity of non-human animals, it does not follow that rationality is devoid of existence. Other beings, such as human beings, are cognitively open to rationality.
Similar to rationality being a property that is cognitively open to human beings but cognitively closed to non-human animals, McGinn concludes that the property of the mind-body connection is cognitively closed to humans but is still “nothing special” (McGinn, 363). This means knowledge of the mind-body connection eludes the cognitive capacity of human beings, but knowledge of the mind-body connection is not necessarily cognitively closed to all beings. This is what McGinn means when he states “the extent of our understanding of facts about the mind is not commensurate with some objective estimate of their intrinsic complexity: we may be good at understanding the mind in some of its aspects but hopeless with respect to others, in a way that cuts across objective differences in what the aspects involve” (McGinn, 363). Despite the fact that knowledge of the mind-body connection is a phenomenon that exceeds human beings cognitive abilities, it does not follow that knowledge of the mind-body connection is a complex, miraculous phenomenon. Rather, human beings only perceive the knowledge of the mind-body connection to be complex and/or miraculous because understanding of this phenomenon exceeds human’s cognitive capacities. This shows that human’s cognitive capacities are not capable of knowing everything there is to know in the universe. For example, knowledge of some phenomena, like knowledge of contradictions, eludes the cognitive capacity of human beings. Therefore, just as human beings do not have the cognitive capacity to comprehend knowledge of contradictions, the human mind cannot comprehend the knowledge of the mind-body connection.
McGinn, Colin. “Can We Solve the Mind–Body Problem?” Mind, vol. 98, no. 391, 1989, pp. 349–366. New Series, http://www.jstor.org/stable/2254848.
You can read McGinn’s full article here.