if its end D. were drawn, the end A. would be moved no otherwise, than if one of the intermediate parts B. or C. were drawn, and the end D. rest quiet. So when I feel _pain_ in my _Foot_, the consideration of Physicks instructs me, that this is performed by the help of _Nerves_ dispersed through the Foot, which from thence being _continued_ like Ropes to the very Brain, whilst they are _drawn_ in the Foot, they also _draw_ the inward parts of the Brain to which they reach, and therein excite a certain _motion_, which is ordain’d by _Nature_ to affect the _mind_ with a _sense_ of _Pain_, as being in the _Foot_. But because these Nerves must pass through the _Shin_, the _Thighs_, the _Loins_, the _Back_, the _Neck_, before they can reach the _Brain_ from the _Foot_, it may so happen, that tho _that part_ of them, which is in the Foot were not touch’d, but only some of their _intermediate parts_, yet the same _motion_, would be caused in the _Brain_, as when the _Foot_ it self is _ill affected_, from whence ’twill necessarily follow, that the _mind_ should _perceive_ the same _Pain_. And thus may we think of any other _Sense_. I understand lastly, that seeing each single motion perform’d in that part of the _Brain_, which _immediately affects_ the _mind_, excites therein only one sort of _sense_, nothing could be contrived more conveniently in this case, than that, of all those _Senses_ which it can cause, it should cause that which _cheifly_, and most _frequently_ conduces to the _conservation_ of an _healthful Man_; And experience witnesses, that to this very _end_ all our _senses_ are given us by _Nature_; and therefore nothing can be found therein, which does not abundantly testifie the _Power_ and _Goodness_ of _God_. Thus for Example, when the Nerves of the Feet are violently and more than ordinarily moved, that motion of them being propagated through the _Medulla Spinalis_ of the Back to the inward parts of the Brain, there it signifies to the mind, that something or other is to be felt, and what is this but Pain, as if it were in the Foot, by which the Mind is excited to use its indeavours for removing the Cause, as being hurtful to the Foot. But the _Nature_ of _Man_ might have been so _order’d_ by _God_, that That same motion in the Brain should represent to the mind any other thing, _viz._ either it self as ’tis in the Brain, or it self as it is in the Foot, or in any of the other forementioned intermediate parts, or lastly any other thing whatsoever; but none of these would have so much conduced to the _Conservation_ of the _Body_. In the like manner when we want drink, from thence arises a certain _dryness_ in the _Throat_, which moves the Nerves thereof, and by their means the inward parts of the Brain, and this motion _affects_ the _mind_ with the _sense_ of _thirst_; because that in this case nothing is more requisite for us to know, then that we _want drink_ for the _Preservation_ of our _Health_. So of the Rest.