Always mistrust negations. They commonly signify blindness and prejudice--except when thoroughly established and carefully formulated in the light of actual experience or mathematical proof. And even then we should be ready to admit the possibility of higher generalisations which may uproot them. They are only safe when thrown into the form of a positive assertion. The impossibility of squaring the circle is not really a negative proposition, except in form. It is safer and more convincing when thrown into the positive and definite form that the ratio of area to diameter is incommensurable. That statement is perfectly clear and legitimate; and the illustration may be used as a parable. A positive form should be demanded of every comprehensive denial; and whatever cannot be thrown into positive form, it is wise to mistrust. Its promulgator is probably stepping out of bounds, into the cheap and easy region of negative speculation. He is like a rationalistic microbe denying the existence of a human being. I have urged that the simple aspect of things is to be considered and not despised; but, for the majority of people, is not the tendency the other way? Are they not too much given to suppose the Universe limited to the simplicity of their first and everyday conception of it? The stockbroker has his idea of the totality of things; the navvy has his. Students of mathematical physics are liable to think of it as a determinate assemblage of atoms and ether, with no room for spiritual entities--no room, as my brilliant teacher, W. K. Clifford, expressed it, no room for ghosts. Biological students are apt to think of life as a physicochemical process of protoplasmic structure and cell organisation, with consciousness as an epiphenomenon. They watch the lowly stages of animal organisms, and hope to imitate their behaviour by judicious treatment of inorganic materials. By all means let them try; the effort is entirely legitimate, and not unhopeful. That which has come into being in the past may come into being under observation in the present, and the intelligence and co-operation of man may help. Why not? The material vehicle would thus have been provided--in this case, without doubt, purposely and designedly--for some incipient phase of life. But would that in the least explain the nature of life and mind and will, and reduce them to simple atomic mechanism and dynamics? Not a whit. The real nature of these things would remain an unanswered question.