I N G E N E R A L. 31 



ly employed as principles by fome philofophers, 

 fuch as, ' Nulla foecundatio extra corpus ;' e- 

 very living creature proceeds from an egg; ge- 

 neration always fuppofes fexes, &c. Thele max- 

 ims mufl. not be taken in an abfolute fenfe ; they 

 fignify no more than that the thing happens 

 more commonly in this manner than in any o- 

 ther. 



Let us then endeavour to find an hypothefis 

 that will be liable to none of thefe defed:s or in- 

 cumbrances ; and, if we (hall not fucceed in ex- 

 plaining the mechanifm employed by Nature for 

 the reprodudion of beings, we fhall, at leaft, be 

 able to approach nearer to the truth than we 

 have hitherto reached. 



In the fame manner as we make moulds by 

 which we can beftow on the external parts of 

 bodies whatever figure we pleafe, let us fuppofe, 

 that Nature can form moulds by which Ihe 

 bcftows on bodies both an external and internal 

 figure ; would not this be one method by which 

 reprodu«£lion might be effeded ? 



Let us firft confider whether this fuppofition 

 be well founded ; let us examine whether it 

 contains any thing that is abfurd or contradic- 

 tory ; and then we fhall difcover what confe- 

 quences may be drawn from it. Though our 

 fenfes reach not beyond the external parts of 

 bodies, we have clear ideas of their different fi- 

 gures and external afTcdions, and we can imi- 

 tate Nature, by rcprelenting external figures int 



dificreat 



