Therefore, it is not at all idle play when we are trained to analyze the entrenched concepts, and point out the circumstances that promoted their justification and usefulness and how they evolved from the experience at hand. [\u2026] I know at least that Hume and Mach have helped me a lot, both directly and indirectly.
Mach clearly recognized the weak points of classical mechanics, and thus came close to demand a General Theory of Relativity \u2013 and this almost half a century ago\! [\u2026] The contemplations of Newton's experiments with the bucket demonstrate how close his mind was to the demands of relativity in a wider sense (relativity of accelerations). Admittedly, the vivid conciousness was missing that [\u2026] we are not in a position to decide by experiments if the falling of a body relative to a coordinate system is caused by the presence of a gravitational field or by a state of acceleration of the coordinate system.