"The human mind is an inadequate agent with which to study olfaction, for the reason that the human olfactory system is relatively insignificant, and that of the other animals give them powers far beyond our comprehension" - Charles Judson Herrick, 1924
What is the cognitive system humans use when manipulating ideas? Humans have over the past 4 million years gained an ability to manipulate ideas that far exceeds any other animal, and have used that ability to develop complex technologies. How exactly has the human species been able to do that, and what is the cognitive system it has evolved for that? In psychiatric science, the field of medical science that studies "disorders" of the ability to manipulate ideas, the concept of "executive function" has gradually developed over the past 50 years, first defined by psychiatrist Karl Pribram in 1973. This "executive function" has the properties that when it is impaired by coercive government, the brain looses the ability to organize the mind, and develops mental illness or "meme illness". These observations, documented and recorded in history itself, suggest that the human executive function is the cognitive system that led to advanced memetic intelligence in humans. What is the evolutionary history of this cognitive system? The neural circuits that have been assigned to the executive function show an overlap with the neural circuitry of the mammalian olfactory system (Fagundo, 2015). Olfaction is the primary sensory modality in mammals (Slotnick, 2009), but not in humans. Not only have humans lost a large part of their olfactory receptors in the past 4 million years (Gilad, 2003; Hughes, 2014), they have also lost most of their olfactory intelligence (Sela, 2010). These observations could be explained with that this primary sensory modality, the olfactory system, was "turned inwards", its attention pointed towards a non-physical environment, the world of ideas, and that the human executive function is a derived trait that co-opted the mammalian olfactory system.
Lee Sela wrote in 2010 that "paradoxically, although humans have a superb sense of smell, they don't trust their nose", and while superb is an exaggeration to appeal to the myth that humans have good olfaction, the latter part is true: humans lost the ability to trust their nose and gained the ability to trust non-sensory, hallucinatory stimuli, belief.