Sentence:  God creates and produces them, but it is according to the Laws of this Species of Beings who were made to propagate one another, so that in this Production earthly Parents are the Instruments. And how far they may be the Instruments in conveying a <WSD>Corruption</WSD> or Pravity, is what we cannot distinctly explain; but to make this alone a Rason for denying it, would argue great Rashness and want of Reflection. 
Meaning of the word marked with <WSD> tags:  (en) Something originally good or pure that has turned evil or impure; a perversion.