_How much of the earth's crust would we have to find_ in this upside down order of the fossils, before we would be convinced that there must be something hopelessly wrong with this theory of Successive Ages which drives otherwise competent observers to throw away their common sense and cling desperately to a fantastic theory in the very teeth of such facts? The science of geology as commonly taught is truly in a most astonishing condition, and doubtless presents the most peculiar mixture of fact and nonsense to be found in the whole range of our modern knowledge. In any minute study of a particular set of rocks in a definite locality, geology always follows facts and common sense; while in any general view of the world as a whole, or in any correlation of the rocks of one region with those of another region, it follows its absurd, unscientific theories. But wherever it agrees with facts and common sense, it contradicts these absurd theories; and wherever it agrees with these theories, it contradicts facts and common sense. That most educated people still believe its main thesis of _a definite age for each particular kind of fossil_ is a sad but instructive example of the effects of mental inertia. IV The reader will find this matter discussed at length in the author's "Fundamentals of Geology"; but here it will be necessary only to draw some very obvious conclusions from the _five facts_ which we have set in opposition to the theory of Successive Ages. 1. The first and absolutely incontrovertible conclusion is that this theory of successive ages must be a gross blunder, in its baleful effects on every branch of modern thought deplorable beyond computation. But it is now perfectly obvious that the geological distinctions as to age between the fossils are fantastic and unjustifiable. No one kind of true fossil can be proved to be older or younger than another intrinsically and necessarily, and the methods of reasoning by which this idea has been supported in the past are little else than a burlesque on modern scientific methods, and are a belated survival from the methods of the scholastics of the Middle Ages.