I care not what subject is taught, if only it be taught well.

There is the greatest practical benefit in making a few failures early in life.

Make up your mind to act decidedly and take the consequences. No good is ever done in this world by hesitation.

The man of science has learned to believe in justification, not by faith, but by verification.

Science reckons many prophets, but there is not even a promise of a Messiah.

From the dawn of exact knowledge to the present day, observation, experiment, and speculation have gone hand in hand; and, whenever science has halted or strayed from the right path, it has been, either because its votaries have been content with mere unverified or unverifiable speculation (and this is the commonest case, because observation and experiment are hard work, while speculation is amusing); or it has been, because the accumulation of details of observation has for a time excluded speculation.

If the twentieth century is to be better than the nineteenth, it will be because there are among us men who walk in Priestley's footsteps....To all eternity, the sum of truth and right will have been increased by their means; to all eternity, falsehoods and injustice will be the weaker because they have lived.