....  To be approved as true
     Such projects must be proved, and carried through.[166]

We would encourage no one to attempt adventures so perilous, but would call to mind in a great example what is the regular march of science.  Newton, after he had discovered the law which regulates the motions of the heavens, sought the confirmation of it in an immense series of calculations.  A true ascetic of science, he imposed on himself a regimen as severe as that of a Trappist monk, in order that his life might be wholly concentrated upon the operations of the understanding; and it was not until after fifteen months of persistent labor that he exclaimed:  “I have discovered it!  My calculations have really encountered the march of the stars.  Glory to God! who has permitted us to catch a glimpse of the skirts of His ways!” And astronomy, placed upon a wider and firmer basis, went forward with new energy.

It is thus that the human mind acquires knowledge.  How then does hypothesis come to be made light of?  How can it be seriously said that we have excluded hypothesis from the sphere of science, whereas the moment the faculty of supposing should cease to be in exercise, the march of science would be arrested; since, except a small number of principles the evidence of which is immediate, all the truths we possess are only suppositions confirmed by experiment?  The reason is here:  Our mind forms a thousand different suppositions at its own will and fancy; and it shrinks from that studious toil which alone puts it in a position to make fruitful suppositions.  We are for ever tempted to be guessing, instead of setting ourselves, by patient observations, on the road to real discoveries.  It is therefore with good reason that theories hastily built up have been condemned, and Lord Chancellor Bacon was right in thinking that the human mind requires lead to be attached to it, and not wings.  Hence the inference has been drawn that the simplest plan would be to cut the wings of thought, without reflecting that thenceforward it would continue motionless.  Because some had abused hypothesis, others must conclude that we could do without it altogether.

Trivial and premature suppositions have therefore discredited hypothesis, by encumbering science with a crowd of vain imaginations; but this encumbrance would have been of small importance but for the obstinacy with which false theories have too often been maintained against the evidence of facts.  If Ampere had found his experiment fail, and had still continued to maintain his statements, he would not have given proof of a happy audacity, but of a ridiculous obstinacy.  Genius itself makes mistakes, and experience alone distinguishes real laws from mere freaks of our thought.  We have maintained the rights of reason in the spontaneous exercise of the faculty of discovery; but let us beware how we ignore the rights of experience.  It alone prepares discoveries; it alone can confirm them.