More than three years ago, I wrote a post about insight, where I showed in the charts of Newton and Einstein the role of strong and well-aspected Moon for scientific intuition.
Having read more about Newton recently, especially the lecture by John Keynes, it is very interesting to see how the strong full Moon in Cancer with aspects to Venus and Jupiter in Newton's chart manifested in his research process:
"I believe that Newton could hold a problem in his mind for hours and days and weeks until it surrendered to him its secret. Then being a supreme mathematical technician he could dress it up, how you will, for purposes of exposition, but it was his intuition which was pre-eminently extraordinary - 'so happy in his conjectures', said De Morgan, 'as to seem to know more than he could possibly have any means of proving'. The proofs, for what they are worth, were, as I have said, dressed up afterwards - they were not the instrument of discovery.
There is the story of how he informed Halley of one of his most fundamental discoveries of planetary motion. 'Yes,' replied Halley, 'but how do you know that? Have you proved it?' Newton was taken aback - 'Why, I've known it for years', he replied. 'If you'll give me a few days, I'll certainly find you a proof of it' - as in due course he did.
Again, there is some evidence that Newton in preparing the Principia was held up almost to the last moment by lack of proof that you could treat a solid sphere as though all its mass was concentrated at the centre, and only hit on the proof a year before publication. But this was a truth which he had known for certain and had always assumed for many years.
Certainly there can be no doubt that the peculiar geometrical form in which the exposition of the Principia is dressed up bears no resemblance at all to the mental processes by which Newton actually arrived at his conclusions.
His experiments were always, I suspect, a means, not of discovery, but always of verifying what he knew already."
"Verifying what he knew already" - that is the strong natal Moon. "Hold a problem in his mind for hours and days and weeks" - that is the natal square of Mercury and Saturn.