Letters

³ It is my opinion that every movement of the mind affects in some degree the body. We know that this is patent even to our senses, dull and sluggish though they are, when the movements of the mind are somewhat vehement, as when we are angry, or sad, or joyful. Whence we may conjecture that, in like manner, when thought is busy, although no bodily effect of the mental act is discernible by us, there may be some such effect discernible by beings of aërial or etherial essence whose perceptive faculty is in the highest degree acute—so much so, that, in comparison with it, our faculties are scarcely worthy to be called perceptive.

Therefore these footprints of its motion, so to speak, which the mind impresses on the body, may perchance not only remain, but remain as it were with the force of a habit; and it may be that, when these are secretly stirred and played upon, they bear thoughts and dreams into our minds, according to the pleasure of the person moving or touching them: and this is done with marvellous facility. For if, as is manifest, the attainments of our earth-born and sluggish bodies in the department of exercise, e.g. in the playing of musical instruments, dancing on the tight-rope, etc., are almost incredible, it is by no means unreasonable to suppose that beings which act with the powers of an aërial or etherial body upon our bodies, and are by the constitution of their natures able to pass unhindered through these bodies, should be capable of much greater quickness in moving whatever they wish, while we, though not perceiving what they do, are nevertheless affected by the results of their activity.

We have a somewhat parallel instance in the fact that we do not perceive how it is that superfluity of bile impels us to more frequent outbursts of passionate feeling; and yet it does produce this effect, while this superfluity of bile is itself an effect of our yielding to such passionate feelings.