"War is a survival among us from savage times and affects now chiefly the boyish and unthinking element of the nation. The wisest realize that there are better ways for practicing heroism and other and more certain ends of insuring the survival of the fittest. It is something a people outgrow. But whether they consciously practice peace or not, nature in its evolution eventually practices it for them, and after enough of the inhabitants of a globe have killed each other off, the remainder must find it more advantageous to work together for the common good."

“So far as thought may peer into the past, the epic of our solar system began with a great catastrophe. Two suns met. What had been, ceased; what was to be, arose. Fatal to both progenitors, the event dated a stupendous cosmic birth.”

“That Mars is inhabited by beings of some sort or other we may consider as certain as it is uncertain what these beings may be.”

“The whole object of science is to synthesize, and so simplify; and did we but know the uttermost of a subject we could make it singularly clear.”

“Are physical forces alone at work there, or has evolution begotten something more complex, something not unakin to what we know on Earth as life?”

“Formulae are the anaesthetics of thought, not its stimulants and to make any one think is far better worth while than cramming him with ill-considered, and therefore indigestible, learning.”

“In the great desert of northern Arizona the traveller, threading his way across a sage-brush and cacti plain shut in by abrupt-sided shelves of land rising here and there some hundreds of feet higher, suddenly comes upon a petrified forest.”