For it is not possible to join serpentine wisdom with columbine innocence, except men know exactly all the conditions of the serpent: his baseness and going upon his belly, his volubility and lubricity, his envy and sting, and the rest; that is, all forms and natures of evil: for without this, virtue lieth open and unfenced.
It is rightly laid down that 'true knowledge is knowledge by causes'. Also the establishment of four causes is not bad: material, formal, efficient and final.
The human understanding is moved by those things most which strike and enter the mind simultaneously and suddenly, and so fill the imagination; and then it feigns and supposes all other things to be somehow, though it cannot see how, similar to those few things by which it is surrounded.
I would by all means have men beware, lest Æsop's pretty fable of the fly that sate [sic] on the pole of a chariot at the Olympic races and said, 'What a dust do I raise,' be verified in them. For so it is that some small observation, and that disturbed sometimes by the instrument, sometimes by the eye, sometimes by the calculation, and which may be owing to some real change in the heaven, raises new heavens and new spheres and circles.
The Scripture saith, The fool hath said in his heart, there is no God; it is not said, The fool hath thought in his heart; so as he rather saith it, by rote to himself, as that he would have, than that he can thoroughly believe it, or be persuaded of it....It appeareth in nothing more, that atheism is rather in the lip, than in the heart of man.
The images of mens wits and knowledge remain in books. They generate still, and cast their seeds in the minds of others, provoking and causing infinite actions and opinions in succeeding ages
For many parts of Nature can neither be invented with sufficient subtlety, nor demonstrated with sufficient perspicuity, nor accommodated unto use with sufficient dexterity, without the aid and intervening of the mathematics, of which sort are perspective, music, astronomy, cosmography, architecture, engineery, and divers others.
Again there is another great and powerful cause why the sciences have made but little progress; which is this. It is not possible to run a course aright when the goal itself has not been rightly placed.