Reserve the great matters till the end, and the small matters give at the beginning.
— Leonardo
“Study me, reader, if you delight in me, because on very few occasions shall I return to the world, and because the patience for this profession is found in very few, and only in those who wish to compose things a new, come, oh men, to see the miracles that such studies will disclose to nature.”
— -Leonardo
Iron rusts from disuse; stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind.

 Science is the observations of things possible, whether present or past. Prescience is the knowledge of things which may come to pass, though but slowly.