Sentence:  [W]hen Man was "fallen", and had abandoned his primitive Innocence, ... he became puſillanimous, and was eaſily ruffled with every little Paſſion within: <WSD>ſupine</WSD>, and as openly expoſed to any Temptation or Aſſault from without. 
Meaning of the word marked with <WSD> tags:  Reluctant to take action due to indifference or moral weakness; apathetic or passive towards something.