One of the problems that the mechanical philosophy had trouble solving was the nature of weight, for it seemed to imply the existence of "spooky" action at a distance (i.e., a hidden force, like an occult sympathy). Indeed, when Newton (1642–1727) developed the first successful scientific theory of gravity, it was not strictly according to the rules of the mechanical philosophy. Therefore mechanistic philosophers criticized the idea of gravitational attraction as an occult force, a charge against which Newton defended himself with his famous statement, "I do not make hypotheses." By this he meant that he made no claims about the existence of hidden gravitational forces, only that the motion of objects could be described as though such forces existed! We may view this as a sort of disingenuous doublespeak, and Newton's critics saw through it too, but it was difficult to oppose the quantitative success of Newton's theory of gravity.
Privately, Newton believed that inert matter could not act at a distance and that universal gravity demonstrated God's active presence in the world (in contrast to the mechanical philosophy) — though without the mediation of a (female) soul — and Newtonian theologians used gravity as evidence for God and a justification for the existing social order.
In Newton's theory of gravitation, and also in his theory of optics, we can see another characteristic of his approach to science, which was to account for visible phenomena (e.g., falling objects, planetary motion, color) in terms of quantifiable but imperceptible properties (gravitational force, wavelength of light). Statements about these unobservable properties were indirectly confirmed or refuted by means of crucial experiments. As we will see, Goethe objected to this theory-laden approach, which he considered remote from the immediate experience of nature and ungrounded in it.
Although he kept it hidden during his lifetime, we know from Newton's notebooks that he was a lifelong student and practitioner of alchemy. (Indeed, there is forensic evidence that his personality oddities were a result of mercury poisoning, a hazard for practicing alchemists at that time.) John Maynard Keynes said Newton was "not the first of the age of reason" but rather "the last of the magicians" and when Newton said that he "stood on the shoulders of giants," he was referring to the sages of the Ancient Theology, including Hermes Trismegistus and Pythagoras. From Pythagorean philosophy in particular he took the idea that Nature is governed to mathematical principles, and that the hidden, fundamental nature of the universe is mathematical (the view also of modern physicists). Indeed, in Newton we find all the elements of contemporary scientific philosophy, which explains and exploits the natural world by means of mathematical principles governing objects, forces, and properties invisible to ordinary perception.Continue to next section.