Additional Notes. 457 



the nature of matter, and in rejecting the idea entertained by 

 most of them, that the sentient principle is a species of matter 

 peculiarly refined and attenuated. 



Dr. Darwin, in his celebrated work, entitled Zoonomia, 

 has offered a physiological theory of mind, which, though 

 more seductive, and, consequently, more dangerous than some 

 others, may be said to contain more crude and inconsistent 

 metaphysics than almost any modern system of materialism 

 of equal reputation. The greater part of his opinions 

 on this subject have been borrowed from other writers; 

 so that, as a pneumatologist, he has little claim to originality, 

 excepting in the method of combining and arranging his doc- 

 trines. The genius of the author, indeed, has given to his 

 metaphysical errors a popular and plausible aspect; and they 

 will probably lead astray thousands of superficial and incon- 

 siderate readers; but they can scarcely mislead inquirers of a 

 more discerning character. 



Dr. Darwin supposes that the sentient principle, or the 

 mind of man, is a subtle fluids which he denominates Sen- 

 sorial Power, or spirit of animation. This Sensorial Power 

 he represents as secreted in the biain, and in the medullary 

 part of the nerves, where it especially resides, and from which. 

 it extends to every part of the body, without being cognizable 

 by our senses, except in its effects. He supposes that the 

 oxygen which enters into combination with the blood in re- 

 spiration, affords the material for the production of Sensorial 

 Power; that this fluid is liable to be accumulated or diminished 

 by various circumstances; that it is constantly expended by 

 stimuli, and is probably too fine to be long retained in the 

 nerves after its production in the brain; and, finally, that it 

 is capable of assuming the property of solidity, or divesting 

 itself of this property at pleasure. 



This Spirit of animation, or Sensorial Power, according to 

 the theory under review, produces contractions or motions in 

 the animal fibre, and these fibrous motions, thus occasioned, 

 are the immediate cause of all our ideas; an idea being de- 

 fined " a contraction, or motion, or configuration of the im- 

 mediate organs of sense." This Spirit has Jour different modes 

 of action ; or, in other words, the mind possesses Jour dif- 

 ferent faculties, which are occasionally exerted, and cause all 

 the contractions of the fibrous parts of the body. These 

 are, 1. The faculty of causing fibrous contractions in con- 

 sequence of the irritations excited by external bodies. 2. 

 The faculty of causing Contractions in consequence of the 



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