Little Question Two of Question One
Whence ecstasy or a forceful rapture is caused
It is asked: whence is ecstasy or rapture caused in souls?
To this it is answered as follows. Because in ecstasies the inferior powers are lulled and the soul often suspends its administration of the body, it must therefore be known that in a human being there is a natural order and mutual connection of three powers: namely, the natural, the animal or sensitive, and the intellectual powers. In the common course, the natural power serves the animal power, and the animal or sensual power serves the intellectual power.
For we see that the natural power requires in its operations the heat and spirits which proceed originally from the heart and are diffused through all the organs of the senses. It is also manifest that, when those organs, interior and exterior, labor more, nature there diffuses more of those spirits to them. Thus it happens in one way that those organs, in an excess of actualization of the sensitive power, are pulled apart or ruptured.
And again, the natural spirits which the digestive power requires are consumed or fail because of the multitude of generations of sensitive spirits. From this it is evident how a vehement, fixed, and profound actualization of the interior sensitive power can lull the interior senses, and likewise weaken the natural powers, because of the connection of those powers.
From this first point follows a second, namely, that every vehement intellectual contemplation of spirits in which the phantasy, or the interior sensitive power, labors excessively enervates the natural powers, lulls the exterior senses, and often induces ecstasy or rapture.
But if, in a vehement and intense or excellent, purely intellectual contemplation, the sensitive powers did not labor, or the natural and animal powers possessed no dependence, or were not impeded, this would have to arise from something other than the connection just described.
These things are from Henry of Hesse, On Genesis.