You Know Only Insofar As You Can

There Cannot Be A Greater Mistake Than That Of Looking Superciliously Upon Practical Applications Of Science. The Life And Soul Of Science Is Its Practical Application.

In Science There Is Only Physics; All The Rest Is Stamp Collecting.

The Only Census Of The Senses, So Far As I Am Aware, That Ever Before Made Them More Than Five, Was The Irishman's Reckoning Of Seven Senses. I Presume The Irishman's Seventh Sense Was Common Sense; And I Believe That The Possession Of That Virtue By My Countrymen-i Speak As An Irishman.

Suppose That You Could Mark The Molecules In A Glass Of Water; Then Pour The Contents Of The Glass Into The Ocean And Stir The Latter Throughly So As To Distribute The Marked Molecules Uniformly Throughout The Seven Seas; If Then You Took A Glass Of Water Anywhere Out Of The Ocean, You Would Find In It About A Hundred Of Your Marked Molecules.

When You Can Measure What You Are Speaking About, And Express It In Numbers, You Know Something About It.