860 METAPHYSICS THE SOURCE OF MYSTERIES. 



served freedom into the actual causes of pheno- 

 mena, and led many to doubt the existence of a 

 First Cause, or that of any spiritual essence, dis- 

 tinct from the properties and laws of gross matter. 



The consequence has been, that we have al- 

 most as many mysteries in Natural Philosophy 

 and Medicine, as in Religion, that the animating 

 principle is still confounded with occult qualities, 

 innate properties, and .undefined powers, that 

 the modus operandi of heat and cold, air and 

 food, exercise and sleep, passions of the mind, 

 medicines and other morbific agents, has never 

 been satisfactorily explained, that the Physi- 

 cian who ought to know the why and wherefore 

 of all he does, " works his way in the dark like 

 a mole, sells his guesses for truths, and doubts 

 his patient to the grave," in short, that " no 

 genuine physiological principle has ever yet been 

 discovered," as truly observed by Mr. Whewell. 

 And it is obvious, that to attempt a philosophical 

 explanation of any of the vital functions, with- 

 out a knowledge of the cause on which they all 

 depend, is " like trying to read a cypher without 

 previously mastering the key." 



But when the science of Medicine shall have 

 arrived at perfection, it will be found to consist 

 chiefly in the art of employing those agents on 

 which the operations of life constantly depend ; 

 or in making the vital principle itself by which 

 the body is formed arid renovated, the grand in- 



