One of the most interesting divisions between modern times and former times becomes clear when you think about the fact that categories like psychology, myth, spirituality, and personal development simply did not exist outside of religion.
A book like Carl Jung’s Liber Novus (also known as The Red Book; finally published and available for the first time within the past 2 years) could not have been imagined as anything besides a holy book. Jung stands between the past and the present in the formulation of a psychological divine well, in the subconscious. Unlike ancient man subsumed within a religious worldview who nonetheless has no awareness of his own projections into it, Jung can rely on the conception of a head above the water without which there would be no water.
To the rationalist, the forms of mind were formerly obscured as divine; to the ecstatic, the mind is experienced as divine. No compromise seems possible, until the breakthrough occurs: these points of view themselves belong to different modes of the mind. This is dramatized by Jung in quasi-religious, intimate, mythological accounts of conversations with himself and within himself. He is part-separated—part-egoized—sufficient to study and ask questions.
It is not an exaggeration to state that once the most important books with the greatest, deepest, densest powers to influence and change minds at their roots could not have existed as anything else besides religious works of prophets, seers, and philosophers. Other books argue over words at the surface, which often seems more safe. Essentially the ambition to engage more deeply would have been known as a religious, mystical impulse rather than a psychological, scientific one.
So-called New Age writers tend to realize this, and identify with and imitate traditions before them, but consequently rely too often on the vagueness and imprecision, and often, sloppiness which mysticism may be allowed in describing phenomena, with consequences for standing upon such loose quicksand. The transition from esoteric mysticism to esoteric psychology (which Jung represents well) has been—at its best—not merely a renaming, but a change in conscientiousness and methodology.
Formerly some sorts of scientific conscientiousness and thorough methodologies were approached intermittently in history by the discipline of esoteric training of the most able minds in certain mystical traditions within a few religions. But these were not only rare; they were typically missing a desire to ground themselves in material-realism as well, or to perform services relevant to humanism instead of priesthoods or some other particular section, which are both almost-uniquely modern tastes.
Now there is an extraordinary opportunity to bring more to bear on the multifaceted problem of understanding and developing the mind deeply and thoroughly (a matter of exercise, in my opinion, more precisely than passively-expressed resources such as knowledge, or awareness). Scientific habits and information may be introduced into the process, as well as determination to achieve more rigorous and accurate descriptions which can be evaluated by comparison to knowledge more broad in origin. Models of the mind (themselves gathered from and invented in the mind) may be evaluated by the needs of life more varied than the hermit, monk, or brahmin, or the academic for that matter. This is in the service of the mind’s realization of itself in all variation and variety.