False facts are highly injurious to the progress of science, for they often endure long; but false views, if supported by some evidence, do little harm, for everyone takes a salutary pleasure in proving their falseness; and when this is done, one path towards error is closed and the road to truth is often at the same time opened.

To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact.

We are not here concerned with hopes or fears, only with truth as far as our reason permits us to discover it.

But then with me the horrid doubt always arises whether the convictions of man's mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy.