There Are Four Chief Obstacles In Grasping

It Is Not Necessarily Impossible For Human Beings To Fly, But It So Happens That God Did Not Give Them The Knowledge Of How To Do It. It Follows, Therefore, That Anyone Who Claims That He Can Fly Must Have Sought The Aid Of The Devil. To Attempt To Fly Is Therefore Sinful.

Reasoning Draws A Conclusion, But Does Not Make The Conclusion Certain, Unless The Mind Discovers It By The Path Of Experience.

[i]f In Other Sciences We Should Arrive At Certainty Without Doubt And Truth Without Error, It Behooves Us To Place The Foundations Of Knowledge In Mathematics, In So Far As Disposed Through It We Are Able To Reach Certainty In Other Sciences And Truth By The Exclusion Of Error.

Argument Is Conclusive, But It Does Not Remove Doubt.

Few Have Attained To Consummate Wisdom In The Perfection Of Philosophy: Solomon Attained To It, And Aristotle In Relation To His Times, And In A Later Age Avicenna, And In Our Own Days The Recently Deceased Robert, Bishop Of Lincoln, And Adam Marsh.