“Seth material” search engine (Jane Roberts)

The body maintains its vitality not only through the physical motion and agility that you perceive, but by microscopic agility, and actions within microseconds, that you do not perceive. There is as much motion, stimulation, and reaction in the interior bodily environment as the body meets through its encounters with the exterior environment. The body must now and then “flush its systems out,” run through its repertoire, raise its temperature (pause), activate its hormonal actions more strongly. In such ways it keeps its system of immunities clear. That system operates always. To some extent, it is a way that the body distinguishes between self and nonself.

Obviously those abilities operate best when you trust them. The body’s systems know what diseases are in the air, so to speak, and will often set up countermeasures ahead of time, giving you what you experience as an indisposition of one kind or another—but an indisposition that is actually a statement of prevention against another condition.