For it is in vain that you polish the mirror if there are no images to be reflected; and it is as necessary that the intellect should be supplied with fit matter to work upon, as with safeguards to guide its working.

But my history differs from that in use (as my logic does) in many things,--in end and office, in mass and composition, in subtlety, in selection also and setting forth, with a view to the operations which are to follow.
For first, the object of a natural history which I propose is not so much to delight with variety of matter or to help with present use of experiments, as to give light to the discovery of causes and supply a suckling philosophy with its first food.

For though it be true that I am principally in pursuit of works and the active department of the sciences, yet I wait for harvest-time, and do not attempt to mow the moss or to reap the green corn.

For I well know that axioms once rightly discovered will carry whole troops of works along with them, and produce them, not here and there one, but in clusters.

And that unseasonable and puerile hurry to snatch by way of earnest at the first works which come within reach, I utterly condemn and reject, as an Atalanta's apple that hinders the race.