I could trust a fact and always cross-question an assertion.

It is right that we should stand by and act on our principles; but not right to hold them in obstinate blindness, or retain them when proved to be erroneous.

There is no more open door by which you can enter into the study of natural philosophy than by considering the physical phenomena of a candle

The book of nature which we have to read is written by the finger of God.

I am busy just now again on Electro-Magnetism and think I have got hold of a good thing but can't say; it may be a weed instead of a fish that after all my labour I may at last pull up.

Nothing is too wonderful to be true, if it be consistent with the laws of nature.

A man who is certain he is right is almost sure to be wrong.