Galileo introduced the world to the two most significant aspects of modern science - its method of inquiry and its criterion of truth - for he was the first major figure to champion the right of the scientists to purchase his research through observation and experiment, uninfluenced by such non-scientific considerations as politics and theology.
Direction g his polemics against the pedantry of his time, Galileo, as his own popularizer, addressed his writings to contemporary laymen. His support of Copernican cosmology against the Church's strong opposition, his development of a telescope and observation of such phenomena as comets and sunspots, his unorthodox opinions as a philosopher of science - these were the central concerns of his career and the subjects of four of his most important writings. These appear here in new, definitive translations by Stillman Drake, with an introductory essay placing them in their biographical and historical context.