In popular writing about “meditation,” skill in the contemplative arts is equated with what is often called “higher consciousness.” The term is a vestige of German Idealism that has been appropriated by denizens of the cultic milieu to evoke and objectify the sense of spaciousness, self-transcendence, and oneness-with-everything that is taken to be the acme of the spiritual life. Although such mental events are comparatively rare, even those experiences classified as “mystical” are entirely normal and consistent with what we know about the physiology of the human body. However, when they are used to support a variety of worldviews that include multiple dimensions, before- and afterlives, alternative physiologies, and Ultimate Realities, we are well advised to stop and think.
There are compelling reasons to exercise caution in making judgements about the nature of the cosmos based on extraordinary experiences. As organisms enmeshed in a network of biological relations, we human beings are constrained in our ability to know the world in which we live and move and have our being. Like flatworms and voles, we cannot see beyond an experiential horizon limited by the sensory apparatus with which the vagaries of evolution has provided us, and by the material interactions dictated by the range of ecological niches we occupy. Our species has developed a set of intellectual tools, a technology, and methods for their use that allow us to greatly extend the normal range of the senses. Even so, experience alone does not give us warrant to speak of an Absolute or Ultimate Reality except, perhaps, in the sense that there are bound to be limits to both sensation and understanding. The sensory realm is Appearance all the way down. We cannot achieve a God’s-eye view, though we might well be able to convince ourselves that we can. Something like that seems to have happened in the case of certain latter-day “enlightenments.”
There are constraints built into the very activity of striving for mental stability, too. Many of the classic methods of “meditation” do not raise consciousness but lower it. Let us take, for instance, a simple attentional exercise, the basic technique of resting the attention on a pre-selected cluster of sensations. Every gain in sensory purity is accompanied in the same moment by a corresponding loss of perceptual leverage. That tradeoff is not a paradox. It is what happens when, in the course of attaining optimum mental stability, the organism makes the most efficient use of diminishing resources. Think of it as a kind of cognitive downshifting. In the course of enacting the contemplative protocol, the information-processing modules in the cerebral cortex that give semantic structure to events are taken offline one after the other. Mental functions that have been fully recruited to the observation and/or construction of a pre-selected range of sensations are unavailable to be deployed elsewhere. As the various parts of a complex mental procedure become overlearned, and the higher cognitive functions are pacified, awareness is gradually diminished, together with the power to report.
Both concentration and decentration, at their most intense, radically simplify experience by adjusting attentive patterns to bypass memory and the mental operations (pattern-recognition, comparison, etc.) that make noticing possible. The power to conceptualize is likewise inhibited and, along with it, the ability to say anything about what is occurring. Where the capacities for language and thought are in abeyance, we cannot speak of knowledge. Jhāna samādhi lands us in such unvarying landscapes as neither-perception-nor-non-perception and the-extinction-of-perception-and-feeling. The cultivation of liberating insight requires us to remember, to compare, to analyze, and to reflect, functions that can sometimes be performed after the fact. If there is anything aptly called Higher Consciousness, we will find it there, in the realm of knowledge.
 The Buddha said as much in the Sabba Sutta (SN 35.23).