Spirit alone can do this, by extending and universalizing the love that is born of instinct. And in doing this it checks and purifies whatever is insistent or ruthless or oppressively personal in the life of instinct. The same extension through spirit is necessary with other instinctive loves, if they are not to be enfeebled or corrupted by thought. The love of husband and wife is capable of being a very good thing, and when men and women are sufficiently primitive nothing but instinct and good fortune is needed to make it reach a certain limited perfection. But as thought begins to assert its right to criticize instinct the old simplicity becomes impossible. The love of husband and wife, as unchecked instinct leaves it, is too narrow and personal to stand against the shafts of satire, until it is enriched by the life of the spirit. The romantic view of marriage, which our fathers and mothers professed to believe, will not survive an imaginative peregrination down a street of suburban villas, each containing its couple, each couple having congratulated themselves as they first crossed the threshold, that here they could love in peace, without interruption from others, without contact with the cold outside world. The separateness and stuffiness, the fine names for cowardices and timid vanities, that are shut within the four walls of thousands upon thousands of little villas, present themselves coldly and mercilessly to those in whom mind is dominant at the expense of spirit. Nothing is good in the life of a human being except the very best that his nature can achieve. As men advance, things which have been good cease to be good, merely because something better is possible. So it is with the life of instinct: for those whose mental life is strong, much that was really good while mind remained less developed has now become bad merely through the greater degree of truth in their outlook on the world. The instinctive man in love feels that his emotion is unique, that the lady of his heart has perfections such as no other woman ever equaled. The man who has acquired the power of impersonal thought realizes, when he is in love, that he is one of so many millions of men who are in love at this moment, that not more than one of all the millions can be right in thinking his love supreme, and that it is not likely that that one is oneself. He perceives that the state of being in love in those whose instinct is unaffected by thought or spirit, is a state of illusion, serving the ends of Nature and making a man a slave to the life of the species, not a willing minister to the impersonal ends which he sees to be good. Thought rejects this slavery; for no end that Nature may have in view will thought abdicate, or forgo its right to think truly. “Better the world should perish than that I or any other human being should believe a lie”—this is the religion of thought, in whose scorching flames the dross of the world is being burnt away.