What did Newton and Leibniz actually discover? Most popular sources credit Newton and Leibniz with the creation and the discovery of calculus. However there are many things that are normally regarded as a part of calculus (such as the notion of a limit with its $\epsilon$-$\delta$ definition) that seem to have been developed only much later (in this case in the late $18$th and early $19$th century).
Hence the question - what is it that Newton and Leibniz discovered?  

I would like to suggest a book written by an italian mathematician (Lucio Russo), namely "The forgotten revolution: how science was born in 300 BC and why it had to be reborn". It contains a lot of interesting things some of which are connected to the story of infinitesimal calculus spreading a (different) light on the works by Newton, Leibniz and Co.
