Only The Fittest Will Survive.

Of All The Differences Between Man And The Lower Animals, The Moral Sense Or Conscience Is By Far The Most Important. This Sense, As Mackintosh Remarks, "has A Rightful Supremacy Over Every Other Principle Of Human Action"; It Is Summed Up In That Short But Imperious Word "ought," So Full Of High Significance. It Is The Most Noble Of All The Attributes Of Man, Leading Him Without A Moment's Hesitation To Risk His Life For That Of A Fellow-creature; Or After Due Deliberation, Impelled Simply By The Deep Feeling Of Right Or Duty, To Sacrifice It In Some Great Cause.

The Young Blush Much More Freely Than The Old But Not During Infancy, Which Is Remarkable, As We Know That Infants At A Very Early Age Redden From Passion.

Seeing Every Height Crowned With Its Crater, And The Boundaries Of Most Of The Lava-streams Still Distinct, We Are Led To Believe That Within A Period, Geologically Recent, The Unbroken Ocean Was Here Spread Out. Hence, Both In Space And Time, We Seem To Be Brought Somewhat Near To That Great Fact — That Mystery Of Mysteries — The First Appearance Of New Beings On This Earth.

This Fundamental Subject Of Natural Selection Will Be Treated At Some Length In The Fourth Chapter; And We Shall Then See How Natural Selection Almost Inevitably Causes Much Extinction Of The Less Improved Forms Of Life And Induces What I Have Called Divergence Of Character.

[alexander Von Humboldt Was The] Greatest Scientific Traveller Who Ever Lived.