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great, and that ceremonies do raise and strengthen it ; allowing, 

 also, that ceremonies may be sincerely used to that end, as a 

 physical remedy, without the least design of thereby procuring 

 the assistance of spirits ; yet ought they still to be held unlawful, 

 because they oppose and contradict that Divine sentence 

 passed upon man for sin : " In the sweat of thy brow thou shalt 

 eat thy bread." For this kind of magic offers those excellent 

 fruits which God had ordained should be procured by labor at 

 the price of a few easy and slight observances. 



There are two other doctrines which principally regard the 

 faculties of the inferior or sensitive soul, as chiefly communicat- 

 ing with the organs of the body the one is of voluntary mo- 

 tion, the other of sense and sensibility. The former has been 

 but superficially inquired into, and one entire part of it is almost 

 wholly neglected. The office and proper structure of the 

 nerves, muscle, etc., requisite to muscular motion, what parts of 

 the body rest while others move, and how the imagination acts 

 as director of this motion, so far that when it drops the image 

 whereto the motion tended, the motion itself presently ceases 

 as in walking, if another serious thought come across our mind, 

 we presently stand still ; with many other such subtilties, have 

 long ago been observed and scrutinized. But how the com- 

 pressions, dilatations, and agitations of the spirit, which, doubt- 

 less, is the spring of motion, should guide and rule the corporeal 

 and gross mass of the parts, has not yet been diligently searched 

 into and treated. And no wonder, since the sensitive soul itself 

 has been hitherto taken for a principle of motion and a function, 

 rather than a substance. But as it is now known to be material, 

 it becomes necessary to inquire by what efforts so subtile and 

 minute a breath can put such gross and solid bodies in motion. 

 Therefore, as this part is deficient, let due inquiry be made con- 

 cerning it. 



Sense and sensibility have been much more fully and dili- 

 gently inquired into, as well in general treatises upon the sub- 

 ject as in particular arts ; viz., perspective, music, etc. ; but how 

 justly, is not to the present intention. And, therefore, we can- 

 not note them as deficient; yet there are two excellent parts 

 wanting in this doctrine : one upon the difference of perception 

 and sense, and the other upon the form of light. In treating of 

 sense and sensibility, philosophers should have premised the 

 difference between perception and sense, as the foundation of 

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