This is the work which, for better and for worse, changed how we humans live forever, uniting the heavens and earth under a satisfying physical theory for the first time. The English translation is smooth enough that it feels like Newton wrote the work 'yesterday'. The introductory sections by Cohen give a detailed overview of the work itself and the broader context in which it was written, which helps in recognising some  mathematical presentation and concepts we no longer use or are unfamiliar with.<br><br>The overall methods used in the Principia have found their use throughout modern physics practice--mathematical modelling, idealisations, theory-mediated measurements, etc. Even with the advent of General Relativity and Quantum Field Theory, we still do physics (in a broad fashion) in a way which is present in this book. No wonder, as a physicist-in-training, I found this work to be an exemplar, despite the less-than-satisfying results in some sections, as Newton himself admitted, of how natural science is to be done (notwithstanding its limitations, as unfortunately we learned the hard way).