primary sources is known to be one of the worst way to study any field, especially when you are not familiar with it, because you lack the context, and because

primary sources is known to be one of the worst way to study any field, especially when you are not familiar with it, because you lack the context, and because they are rarely written for the profane. This is all the more true for maths: have you ever read a math books from the XIXth century ? This is almost impenetrable, if only because of the formulation