ON GENERATION. 365 



Instrumental efficients, then, are of different kinds : some, 

 according to Aristotle, are factive, others active ; some have 

 110 capacity any way unless conjoined with another prior effi- 

 cient, as the hand, foot, genital organs, &c. with the rest of the 

 body; others have an influence even when separate and distinct, 

 as the seminal fluid and the ovum. Some instruments, again, 

 have neither motion nor action beyond those that are imparted 

 to them by the prime efficient ; and others have peculiar in- 

 herent principles of action, to which nature indeed allows no 

 motion in the business of generation, though she still uses their 

 faculties, and prescribes them laws or limits in their operations, 

 not otherwise than the cook makes use of fire in cooking, and 

 the physician of herbs and drugs in curing diseases. 



Sennert, that he may uphold the opinion he had espoused 

 of the vital principle (anima) being present in the semen, and 

 the formative faculty of the chick being extant in the egg, as- 

 serts that not only is the egg, but the semen of the cock, en- 

 dowed with the living principle of the future chick. Moreover, 

 he distinctly denies that there is any separate instrumental 

 efficient ; and says, that that only ought to be entitled " instru- 

 ment" which is conjoined with the prime efficient ; and that 

 only " instrumental efficient," which has no motion or action save 

 that which is imparted to it by the prime efficient, or which is 

 continuously and successively received, and in virtue of which 

 it acts. And on this ground he rejects the example of projec- 

 tiles, which have received force from the projecting agent, and, 

 separated from it, act nevertheless ; as if swords and spears Avere 

 properly to be called warlike weapons, but arrows and bullets 

 to be refused this title. He also rejects the argument derived 

 from the republic, denying thereby that magistrates, counsel- 

 lors, or ministers, are instruments of government; although 

 Aristotle regards a counsel as an efficient, and in express terms 

 calls a minister an instrument. 1 Sennert likewise denies the 

 example of automata; and says and gainsays much besides, 

 with a view to confirming himself in his position, that the 

 semen and the egg are possessed of a living principle (anima), 

 and are not mediate or instrumental, but principal agents. 

 Sennert, nevertheless, as it were compelled by the force of 



1 I'oLit. lib. i, cap. 4. 



