Although nature commences with reason and ends in experience it is necessary for us to do the opposite, that is to commence with experience and from this to proceed to investigate the reason.

Because, if it were all-pervading and the same in every part, there would have been no need to make the instruments of the senses meet in one centre and in one single spot; on the contrary it would have sufficed that the eye should fulfil the function of its sensation on its surface only, and not transmit the image of the things seen, to the sense, by means of the optic nerves, so that the soul - for the reason given above - may perceive it in the surface of the eye.

How so many absurd rules of conduct, as well as so many absurd religious beliefs, have originated, we do not know; nor how it is that they have become, in all quarters of the world, so deeply impressed on the minds of men; but it is worthy of remark that a belief constantly inculcated during the early years of life, while the brain is impressionable, appears to acquire almost the nature of an instinct; and the very essence of an instinct is that it is followed independently of reason.

The very essence of instinct is that it's followed independently of reason.

My faith is in the unknown, in all that we do not understand by reason; I believe that what is beyond our comprehension is a simple fact in other dimensions, and that in the realm of the unknown there is an infinite power for good.

Reason has always existed, but not always in a reasonable form.