If this biography were really as good as some reviewers claim, it would probably still be in print. Gottschalk uses the example of Marat’s pre-revolutionary scientific failure to suggest that his political radicalism was largely fuelled by embitterment at his rejection by the Royal Academy of Sciences, and that his later reincarnation as a revolutionary journalist was an opportunistic intervention founded upon a “martyr complex”. He concludes that any influence Marat wielded over the People derived from his uncompromising devotion to the revolutionary cause rather than his political theories. Whether this is true or not, it is no reason to dismiss Marat's ideas out of hand. His progressive views on women, slaves and the poor as well as the pragmatic need for a determined revolutionary vanguard leadership were light years ahead of most of his contemporaries. Following its translation into French in 1929, this biography has dominated the field for over sixty years, and much received wisdom about Marat can be traced back to it. This is not to say it lacks merit, merely to be extremely wary while reading it, keep an open mind and try, where possible, to read the full extracts in their context of production.
The best current biography by far is by Olivier Coquard, but if you don't read French, then Clifford Conner is a good starting-point (but not the Pluto edited edition), especially for the pre-revolutionary material, although he wears his politics on his sleeve so his reassessment swings too far the other way.
Finally, can we please knock this idea on the head that Marat was a ruthless, amoral psychopath. His calls for heads to roll, while hard to understand from our comfortable contemporary viewpoint, were relatively infrequent, always tied to a specific threatening situation, and often rhetorical. The letters of Manon Roland, so often lauded as a moderate, as indeed the published views of numerous other journalists, were often far more chilling in their callous attitudes to spilt blood, and their reckless calls for war or for the mob to come out onto the street. Like Pandora's box, once the lid was opened it was hard to close it back up again. For many, Marat became, and still is, a convenient scapegoat for all the Revolution's excess, even though he was dead before the Terror even began. Perhaps the most interesting question, while reading this book, is to keep asking yourself why…