Besides the political writings of grave argument for which he found time, these five years teem with the results of work.

In the year before his death he sketched out once more, in a letter to a Venetian correspondent, Fra Fulgenzio, the friend of Sarpi, the plan of his great work, on which he was still busy, though with fast diminishing hopes of seeing it finished.

To another foreign correspondent, a professor of philosophy at Annecy, and a distinguished mathematician, Father Baranzan, who had raised some questions about Bacon's method, and had asked what was to be done with metaphysics, he wrote in eager acknowledgment of the interest which his writings had excited, and insisting on the paramount necessity, above everything, of the observation of facts and of natural history, out of which philosophy may be built.

But the most comprehensive view of his intellectual projects in all directions, "the fullest account of his own personal feelings and designs as a writer which we have from his own pen," is given in a letter to the venerable friend of his early days, Bishop Andrewes, who died a few months after him.

Part, he says, of his _Instauratio_, "the work in mine own judgement (_si nunquam fallit imago_) I do most esteem," has been published; but because he "doubts that it flies too high over men's heads," he proposes "to draw it down to the sense" by examples of Natural History.