Page:Cyclopaedia, Chambers - Volume 2.djvu/709

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Sleep, when the Nerves are in a State of Relaxation ; In Effect, from a ftria Examination of the feveral the Soul does not then receive any new Sen fation. : But Senfes, it appears, that fenfible Objefls act no otherwife if the Nerves happen to be agitated in the Brain, by upon the Body, for the producing of Senfation, than by the Courfe of the Animal Spirits, or any other Caule; the excitmg a Change in the extreme Surface of the Fibres Soul perceives fomething, though the farts of thole of the Nerves. The Quality of which Change depends Nerves, that are out of the Brain, diffufed through the on the Figure, Bulk, Hardnefs, and Motion of the Objeft - feveral Parts of the Body, remain at perfedt Reft : as like- ib that according to all Appearances, the mott diftcrcric wife is frequently the Cafe in Sleep. Laflly, obferve, by Objefts, which fhould agree in thefe Four Circumftances the way, that Experience tells us, we may iometimes_/ee/ would produce the fame Sulfation. From the various Tex! Fain in Parts of the Body that have been entirely cue ture of the Objefl; the Diverfity of the Nerve atMed. off; by reafon the Fibres in the Brain correfponding to the different Fabric of the Organ of Senfe ; the different them, being agitated in the fame Manner as if they were Place in the Medulla of the Brain, where the Net really hurt; the Soul feels a real Pain in thole imaginary Parts. AH thefe Things {hew evidently, that the Soul refides immediately in that Part of the Brain wherein the Nerves of all the Organs of Senfe terminate : we mean, 'tis there it perceives all the Changes that happen with regard to the Objecfs that caufe them, or that have been ufed to caufe them ; and, that it only perceives what paffes out of this Part, by the Me- diation of the Fibres terminating in it. See Nerve, F'ibre, ££?c.

Thefe Things premifed, 'twill not be difficult to ex- plain how Seufilion is perform'd ; the Manner whereof

Nerve

antes ; and the different Degree of Motion, wherewith the Action of the Objefl is applied, arife various Senfa- tions, and Ideas, in the Mind : none of which repreient any thing in the A&ion of the Objefl, or in the Paffion of the Organ. And yet the fame Aftion of the fame Object, on the fame Organ, always produce the fame Senfation or Idea : And the fame Ideas neceflarily follow the fame Difpofition ot the fame fenfible Organ, in the fame manner as if the Idea perceiv'd, were the natural and neceffary Effect of the Action on the Organ. See Idea.

SENSE, a Faculty of the Soul, whereby it perceives

may be conceiv'd from what follows. When the Point external Objects, by means of fome Action or Impreffion of a Needle, for Inftance, is preffed againft the Hand, made on certain Parts of the Body, called Organs of that Point flirs and feparates the Fibres of the Flefh ; Senfe, and propagated by them to the Senfory. which Fibres are extended from that Place to the Brain, Some ufe the Word Senfe in a greater Latitude ; and and when we are awake, are in fuch a Degree of Ten- define it a Faculty whereby the Soul perceives Ideas or lion as that they cannot be ftirr'd without fhaking thofe Images of Objects, either convey'd to it from without, of the Brain. If rhen, the Motion of the Fibres of the by the Impreffion of Objects themfelves, or excited Hand be gentle, that of the Fibres of the Brain will be within by fome Effort of the Soul on the Senfory it felf: fo too ; and if the firft be violent enough to break any Under this Notion, Senfe becomes diftinguifhible into thing in the Hand, the laff will be ftronger and more two Kinds, External and Internal ; correfponding to the violent in Proportion. In like Manner, if the Hand be twofeverai Manners wherein the Images of the Objecfs held to the Fire ; the little Particles of the Wood it perceiv'd, either are occafion'd, and prefented to the Mind, throws off in great Numbers, and with a gteat deal of W2. immediately from without, or from wirhin ; that is Violence, ftriking againft thele Fibres, and communica- either by what we commonly call the Five External Senfes, ting a Part of their Agitation thereto; if the Action be Hearing, Seeing., £J?c. or by the Internal ones, Imagimti- moderate, that of the Extremities of the Fibres of the on. Memory, and Attentkn; to which fome add Hunger and Brain correfponding to thofe of the Hand, will be mode- Thirf. But as thefe Internal Senfes are not ordinarily rate likewiie : If it be violent enough to feparate any confider'd in the Notion of Senfes, nor implied under of the Parts of the Hand, as it happens in Burning ; the the Word Senfe ; but are thus only denominated from Ana- Motion of the Fibres in the Brain will be proportionably logy ; we fruit wave them to be further, confider'd, under more violent. This is what befals the Body, when Ob- their refpective Articles Imagination, Memory Sec. jects ftrike upon it. We are now to confider how the External Senfes, or, fimply, 'The Senfes, in their general Mind is affected. _ Signification, ate the Means whereby rhe Soul apprehends, The Mind, we have obferv'd, refides principally, if we or takes Cognizance of External Objects • the Means we may 6e allow'd to fay fo, in that Part of the Brain mean, both on the Part of the Mind, and of the Body, where all the Fibres of the Nerves terminate. It at- The Means, on the Part of the Mind, are always the tends here, as its Senfory, or Office, to look to the Pre- fame ; it being one and the fame Faculty, whereby we fervation of all the Parts of the Body; and, ofconfe- See, Hear, t$c. The Means, on the Part of rhe Body, quence, muff be here advertifed of all the Changes that are different; as different as are the Objects we are con- happen, and muft be able to diftingmfh between cern'd to perceive : For the Being, and Well-being of thole agreeable to the Conftitution of the Body, and tV "" A"!""' U~; nn .u„ i?„j t.-_. — l.j :.. ^ r -_ thofe hurtful thereto. Any other, abfolute Knowledge, without a Relation to the Body, were ufelefs. Thus, though all the Changes in our Fibres, do, in Reality confifl in Motions, which ordinarily only differ as tc more and lets ; 'tis neceffary the Soul fhould look on them as Changes effentially different ; for though in themfelves they differ but very little, yet, with regard to Prefervation of the Body, they are to be look'd on as effentially different.

The Motion, for Inftance, which caufes Pain, frequent- ly differs exceedingly little from that which occafions Titillation: 'Tis not neceffary there fhould be an Effen- tial Difference between thofe two Motions, but 'tis ne

the Animal, being the End, Nature had in View giving him any Perception of external Bodies ; by this, the Meafure and Manner of that Perception is regulated ; and we have fo many Ways of perceiving, and of per- to ceiving fo many Things, as the Relation we bear to external Bodies renders neceffary for the Prefervation, ££c of our Being. Hence thofe feveral Organs of Senfe, call'd Eye, Ear, Nofe, 'Palate, and the uniyerfal one Cutis; each of which is fo difpofed as to give it fome Repre- fentation and Report to the Mind, of the State of exter- nal Things, the Nearnefs, Convenience, Hurttulnefs, and other Habitudes ; and each of them a different one, ac- cording to the Degree, and Immediatenefs, J£?c. of the Danger, or Conveniency. And hence the feveral Exercifes

ceffary there be an Effential Difference between the of thofe Organs, Hearing, Seeing, Smelling, falling, and Pain and the Tickling thofe two Motions occafion in Feeling.

the Soul ; for the Agitation of the Fibres, which accom- For the general Manner wherein our Senfes nEl ; or, panies the Titillation, informs the Soul of the good more properly, the Manner wherein we become Setiftbh, State of the Body, that it is able to refift the Im- that is, perceive external Objefls ; See Sensation. preffion of the Objeas, and that it need not apprehend For the patticular Senfes, or, more properly, the parti- its being hurt: But the Motion, which occafions Pain, cular Manners, wherein we become fenfible, by the parti- being fomewhat more violent, is capable of breaking cular Organs of Senfe; See Hearing, Seeing, Smei- fome of the Fibres of the Body ; wherefore 'tis neceffa- lino, igc.

For the feveral Organs of Senfe, miniftring to the fe- veral Manners of Senfation ; See Eve, Ear, Nose, &. Pliny obferves, That of all the Senfes, Feeling and Tatting are what Man has in the greatefl Perfeaion: As to Seeing he is excelled by the Eagle, £j?c. as to Smel- ling, by the Vulture, Jjfc. and as to Hearing, by the Mole, even when hid under Ground. Nat. Hift. Lib. to. The

ry rhe Soul be advertized hereof by fome difagreeable

Senfation, that it may provide againft it. Thus, though

all the Motions which pafs in the Body only differ in

themfelves, as to more or lefs, yet, when confidered, with

regard to the Prefervation of Life, rhey may be laid to be

efTentiaily different : For this Reatbn it is, that the Soul

does notperceive the Shakes, or Motions themfelves, which

Objeas excite in the Fibres of the Flefh : It would be Senfes have been fbmerimes found greatly fliarp'ened and

ufelefs to perceive rhem ; and (he would never be able, improved by Difeafes. Mr. Boyle mentions a Gentle-

thence, to learn whether the Objeas were capable of doing Hurt or Good. But fhe perceives herfelf affeaed with SevfatkttS, which differ effenrially, and which fhew- ing precifely the Qualities of the Objects, as they regard the Body, make her perceive, diftinaiy, whether or no thofe Objeas are capable of hurting it.

man, who, during a Diflemper he had in his Eyes, had his Organs of Sight broughr to be fo tender, that when he waked in the Night, he could, for a while, plainly fee and diftinguifh Colours, and other Objeas ; and the fame Author gives an Inftance of another Per.'bn, who, after getting half-fuddled with Claret, if he waked in

the