When the articles which make up the substance of this book were appearing in "The Evening News," a very courteous correspondent wrote to me about one of them. He avowed himself a mathematician; and he protested against a paragraph which seemed to him to cast a shadow of doubt on Euclid's definitions. I had said: "It is written that no man hath seen God at any time; but has any man seen a Point or a Line or a Plane Surface at any time? A Point has neither parts nor magnitude—I seem to remember—but only position. A Line is length without breadth; which is a thing utterly inconceivable."
My friendly mathematician re-