From John Aubrey, A Brief Life of Thomas Hobbes, 1588-1679:

As I remember, there were others likewise did preach his doctrine. This little MS treatise grew to he his book De Cive, and at last grew there to be the so formidable Leviathan; the manner of writing of which book (he told me) was thus. He walked much and contemplated, and he had in the head of his cane a pen and ink-horn, carried always a note-book in his pocket, and as soon as a thought darted, he presently entered it into his book, or otherwise he might perhaps have lost it. He had drawn the design of the book into chapters etc so he knew whereabout it would come in. Thus that book was made….

[F]rom 1660 till the time he last went into Derbyshire, he spent most of his time in London at his lord’s (viz at Little Salisbury House; then, Queen Street; lastly, Newport House), following his contemplation and study. He contemplated and invented (set down a hint with a pencil or so) in the morning, hut compiled in the afternoon….

He rose about seven, had his breakfast of bread and butter; and took his walk, meditating till ten; then he did put down the minutes of his thoughts.

He had an inch thick board about sixteen inches square, whereon paper was pasted. On this board he drew his lines (schemes). When a line came into his head, he would, as he was walking, take a rude memorandum of it, to preserve it in his memory till he came to his chamber. He was never idle; his thoughts were always working.

His dinner was provided for him exactly by eleven, for he could not now stay till his lord’s hour-that is, about two: that his stomach could not bear.

After dinner he took a pipe of tobacco, and then threw himself immediately on his hed, with his band off, and slept (took a nap of about half an hour).

In the afternoon he penned his morning thoughts….

Besides his daily walking, he did twice or thrice a year play at tennis (at about 75 he did, it); then went to bed there and was well rubbed. This he did believe would make him live two or three years the longer. In the country, for want of a tennis court, he would walk up hill and down hill in the park, till he was in a great sweat, and then give the servant some money to rub him.