"As we divided natural philosophy in general into the inquiry of causes, and productions of effects: so that part which concerneth the inquiry of causes we do subdivide according to the received and sound division of causes. The one part, which is physic, inquireth and handleth the material and efficient causes; and the other, which is metaphysic, handleth the formal and final causes."

“I confess that I have as vast contemplative ends, as I have moderate civil ends: for I have taken all knowledge to be my province; and if I could purge it of two sorts of rovers, whereof the one with frivolous disputations, confutations, and verbosities, the other with blind experiments and auricular traditions and impostures, hath committed so many spoils, I hope I should bring in industrious observations, grounded conclusions, and profitable inventions and discoveries; the best state of that province. This, whether it be curiosity, or vainglory, or nature, or (if one take it favourably) philanthropia, is so fixed in my mind as it cannot be removed. And I do easily see, that place of any reasonable countenance doth bring commandment of more wits than of a man's own; which is the thing I greatly affect.”

“The law of nature teaches me to speak in my own defence: With respect to this charge of bribery I am as innocent as any man born on St. Innocents Day. I never had a bribe or reward in my eye or thought when pronouncing judgment or order (…). I am ready to make an oblation of myself to the King. (17 April 1621)”

“He that defers his charity 'till he is dead, is (if a man weighs it rightly) rather liberal of another man's, than of his own.”

“Ne mireris, si vulgus verius loquatur quam honoratiores; quia etiam tutius loquitur.”

“I bequeath my soul to God (…). My body to be buried obscurely. For my name and memory, I leave it to men's charitable speeches, and to foreign nations, and the next age.”

“Credulity in arts and opinions (…) is likewise of two kinds viz., when men give too much belief to arts themselves, or to certain authors in any art. The sciences that sway the imagination more than the reason are principally three viz., astrology, natural magic, and alchemy (…). Alchemy may be compared to the man who told his sons that he had left them gold, buried somewhere in his vineyard; while they by digging found no gold, but by turning up the mould about the roots of the vines procured a plentiful vintage. So the search and endeavours to make gold have brought many useful inventions to light.”