Chapter XXVIII: Madam,

Concerning _Dimness_ of _Sight_, which your _Author_ will have to _proceed from the deficiency of the Animal Spirits_,[1] My meaning in short is, That when sight is dim, though the sensitive organs are perfect, this dimness is caused by the alteration onely of the sensitive motions in the organs, not moving to the nature of sight. And so is made Deafness, Dumbness, Lameness, and the like, as also Weariness; for the Relaxation of strength in several parts, is onely an alteration of such sorts of motions which make the nerves strong; and if a man be more dull at one time, then at another, it is that there are not so many changes of motions, nor so quick motions at that time, as at another; for Nature may use more or less force as she pleases: Also she can and doth often use opposite actions, and often sympathetical and agreeable actions, as she pleases; for Nature having a free power to move, may move as she will; but being wise, she moves as she thinks best, either in her separating or uniting motions, for continuance, as well as for variety. But if, according to your _Author_, the Immaterial Soul should determinate matter in motion, it would, in my opinion, make a confusion; for the motions of the Matter would often oppose and cross the motions of the Immaterial Soul, and so they would disagree, as a King and his Subjects, (except God had given the Soul an absolute power of command, and restrained matter to an irrisistible and necessitated obedience; which, in my opinion, is not probable:) By which disagreement, Nature, and all that is in Nature, would have been quite ruined at this time; for no kinds, sorts, or particulars, would keep any distinction, if Matter did not govern it self, and if all the parts did not know their own affairs, abilities, offices, and functions: Besides, it would, to my thinking, take up a great deal of time, to receive commands in every several action, at least so much, that for example, a man could not have so many several thoughts in so short a time, as he hath. But concerning the Animal Spirits, which your _Author_ calls the Instruments, Organs and Engines of the Incorporeal Soul; I would fain know, whether they have no motion but what comes from the Soul, or whether they have their own motion of themselves? If the first, then the Soul must, in my opinion, be like a Deity, and have a divine Power, to give and impart Motion; if the second, then the spirits being material, it follows that Matter hath motion of it self, or is self-moving; But if the Immaterial natural Soul can transfer her gifts upon corporeal matter, then it must give numerous sorts of motions, with all their degrees; as also the faculty of figuring, or moving figuratively in all corporeal Matter: Which power, in my judgment, is too much for a Creature to give. If you say, the Immaterial Soul hath this power from God; I answer, Matter may have the same; and I cannot imagine why God should make an Immaterial Spirit to be the Proxy or Vice-gerent of his Power, or the _Quarter-master General of his Divine Providence_, as your _Author_ is pleased to style it,[2] when he is able to effect it without any Under-Officers, and in a more easie and compendious way, as to impart immediately such self-moving power to Natural Matter, which man attributes to an Incorporeal Spirit. But to conclude, if the Animal Spirits be the Instruments of the Incorporeal Soul, then the Spirits of Wine are more powerful then the Animal Spirits, nay, then the Immaterial Soul her self; for they can put them and all their actions quite out of order: the same may be done by other material things, Vegetables, Minerals, and the like. And so leaving this discourse to your better consideration, I take my leave for this time, and rest,

Madam,

_Your faithful and affectionate Friend,_

_and Servant._

[1] _Immort. of the Soul. Book_ 2. _ch._ 8.

[2] _Immort. of the Soul. Book_ 3. _c._ 13.