The calculus as algebra -- The mathematician, the historian, and the history of mathematics -- Who gave you the epsilon? Cauchy and the origins of rigorous calculus -- The changing concept of change: the derivative from Fermat to Weierstrass -- The centrality of mathematics in the history of western thought -- Descartes and problem-solving -- The calculus as algebra, the calculus as geometry: Lagrange, Maclaurin, and their legacy -- Was Newton's calculus a dead end? the continental influence of Maclaurin's treatise of fluxions -- Newton, Maclaurin, and the authority of mathematics -- Why should historical truth matter to mathematicians? dispelling myths while promoting maths -- Why did Lagrange "prove" the parallel postulate?.