▁latter ▁city ▁he ▁met ▁H erman ▁Wille m ▁Da end els , ▁later ▁a ▁fellow - re volution ary . ▁ ▁He ▁had ▁been ▁intended ▁to ▁study ▁law , ▁but ▁began ▁to ▁study ▁philosophy ▁and ▁medicine ▁instead ▁( 1 7 7 7 – 1 7 8 3 ). ▁ ▁He ▁wrote ▁his ▁dis sert ations ▁on ▁the ▁ ▁theory ▁of ▁the ▁imagination ▁and ▁a ▁medical ▁survey ▁of ▁the ▁d ys ent ery ▁ep ide mic ▁that ▁ra ged ▁in ▁N ij m egen ▁in ▁ 1 7 8 3 . ▁ ▁He ▁established ▁himself ▁as ▁a ▁phys ician ▁in ▁Amsterdam , ▁after ▁he ▁had ▁decl ined ▁an ▁offer ▁of ▁a ▁professor ate ▁in ▁medicine ▁at ▁Fran ek er ▁university . ▁ ▁He ▁was ▁a ▁member ▁of ▁the ▁ ▁Con cord ia ▁et ▁Libert ate ▁gen oot schap ▁and ▁of ▁Ma at sch app ij ▁tot ▁N ut ▁van ▁' t ▁Alg eme en . ▁ ▁In ▁the ▁Felix ▁Mer itis ▁gen oot schap ▁he ▁presented ▁physics ▁experiments ▁and ▁lect ured ▁on ▁art ▁history , ▁while ▁taking ▁less ons ▁in ▁painting . ▁He ▁refused ▁a ▁request ▁to ▁take ▁charge ▁of ▁organ izing ▁military ▁in und ations ▁around ▁Amsterdam ▁during ▁the ▁Patri ot ▁Revol t ▁of ▁ 1 7 8 5 – 7 . ▁This ▁may ▁have ▁contributed ▁to ▁the ▁fall ▁of ▁Amsterdam ▁to ▁the ▁Pr us si ans ▁in ▁ 1 7 8 7 , ▁when ▁they ▁interven ed ▁in ▁favor ▁of ▁stad th older ▁William ▁V . ▁ ▁K ray en hoff ▁was