Thread by @YUKOWAS

§. 3. Thirdly, how the soul directs the spirits for the motion of the body according to the several animal exigents; is as perplex in the theory, as either of the former. For the meatus, or passages, through which those subtle emissaries are conveyed to the respective members,

being so almost infinite, and each of them drawn through so many meanders,
cross turnings, and divers roads, wherein other spirits are continually a-journeying; it is wonderful,

that they should exactly perform their regular destinations without losing their way in such a wilderness: neither can the wit of man tell how they are directed. For that they are carried by the manuduction of a Rule, is evident from the constant steadiness

and regularity of their motion into the parts,
where their supplies are expected: but, what that regulating efficiency should be, and how managed; is not easily determined. That it is performed by mere Mechanism, constant experience confutes; which assureth us,

that our spontaneous motions are under the Imperium of our will. At least the first determination of the spirits into such or such passages, is from the soul, what ever we hold of the after conveyances; of which likewise I think,

that all the philosophy in the world cannot make it out to be purely mechanical.
But yet though we gain this, that the soul is the principle of direction, the difficulty is as formidable as ever.

For unless we allow it a kind of inward sight of the anatomical frame of its own body of every vein, muscle, and artery; of the exact site, and position of them, with the several windings, and secret chanels:

it is as unconceivable how it should be the directrix of such intricate motions, as that a blind man should manage a game at chess, or marshal an army.
But this is a kind of knowledge, that we are not in the least aware of:

yea many times we are so far from an attention to the inward direction of the spirits, that our employed minds observe not any method in the outward performance; even when 'tis managed by variety of interchangeable motions, in which a steady direction is difficult,

and a miscarriage easy. Thus an artist will play a lesson on an instrument without minding a stroke; and our tongues will run divisions in a tune not missing a note, even when our thoughts are totally engaged elsewhere:

which effects are to be attributed to some secret art of the soul, which to us is utterly occult, and without the ken of our intellects.

JOSEPH GLANVILL