The Final Upshot Of Thinking Is The

Mathematics Is Purely Hypothetical: It Produces Nothing But Conditional Propositions.

Effort Supposes Resistance.

This Branch Of Mathematics [probability] Is The Only One, I Believe, In Which Good Writers Frequently Get Results Which Are Entirely Erroneous.

Upon This First, And In One Sense This Sole, Rule Of Reason, That In Order To Learn You Must Desire To Learn, And In So Desiring Not Be Satisfied With What You Already Incline To Think, There Follows One Corollary Which Itself Deserves To Be Inscribed Upon Every Wall Of The City Of Philosophy: Do Not Block The Way Of Inquiry.

Some Think To Avoid The Influence Of Metaphysical Errors, By Paying No Attention To Metaphysics; But Experience Shows That These Men Beyond All Others Are Held In An Iron Vice Of Metaphysical Theory, Because By Theories That They Have Never Called In Question.