Progress Has Been Much More General Than

Mere Chance ... Alone Would Never Account For So Habitual And Large An Amount Of Difference As That Between Varieties Of The Same Species.

We Are Always Slow In Admitting Any Great Change Of Which We Do Not See The Intermediate Steps

Although I Am Fully Convinced Of The Truth Of The Views Given In This Volume Under The Form Of An Abstract, I By No Means Expect To Convince Experienced Naturalists Whose Minds Are Stocked With A Multitude Of Facts All Viewed, During A Long Course Of Years, From A Point Of View Directly Opposite To Mine... I Look With Confidence To The Future, To Young And Rising Naturalists, Who Will Be Able To View Both Sides Of The Question With Impartiality.

Now When Naturalists Observe A Close Agreement In Numerous Small Details Of Habits, Tastes And Dispositions Between Two Or More Domestic Races, Or Between Nearly-allied Natural Forms, They Use This Fact As An Argument That All Are Descended From A Common Progenitor Who Was Thus Endowed; And Consequently That All Should Be Classed Under The Same Species. The Same Argument May Be Applied With Much Force To The Races Of Man.

It May Be Doubted Whether Any Character Can Be Named Which Is Distinctive Of A Race And Is Constant.