Appeared online in Journal of Historical Biography 5 (Spring 2009): 48-83. Extended critique of Clarke on Descartes’ early scientific career foreshadowed arguments in my Descartes-agonistes (2013). This review should be compared with more sympathetic approach to other parts of Des Clarke’s legacy in Schuster paper ‘Did Descartes Teach a Philosophy of Science or Pursue Strategies of Natural Philosophical Systematization’ (2017), also posted in research section.