In a refined nature these sensuous premonitions of sympathy are seldom misleading. Liking cannot, of course, grow into friendship over night as it might into love; the pleasing impression, even if retained, will lie perfectly passive and harmless in the mind, until new and different impressions follow to deepen the interest at first evoked and to remove its centre of gravity altogether from the senses. In love, if the field is clear, a single glimpse may, like Tristan’s potion, produce a violent and irresistible passion; but in friendship the result remains more proportionate to the incidental causes, discrimination is preserved, jealousy and exclusiveness are avoided. That vigilant, besetting, insatiable affection, so full of doubts and torments, with which the lover follows his object, is out of place here; for the friend has no property in his friend’s body or leisure or residual ties; he accepts what is offered and what is acceptable, and the rest he leaves in peace. He is distinctly not his brother’s keeper, for the society of friends is free. [Sidenote: The refracting human medium for ideas.] Friendship may indeed come to exist without sensuous liking or comradeship to pave the way; but unless intellectual sympathy and moral appreciation are powerful enough to react on natural instinct and to produce in the end the personal affection which at first was wanting, friendship does not arise. Recognition given to a man’s talent or virtue is not properly friendship. Friends must desire to live as much as possible together and to share their work, thoughts, and pleasures. Good-fellowship and sensuous affinity are indispensable to give spiritual communion a personal accent; otherwise men would be indifferent vehicles for such thoughts and powers as emanated from them, and attention would not be in any way arrested or refracted by the human medium through which it beheld the good. [Sidenote: Affection based on the refraction.] No natural vehicle, however, is indifferent; no natural organ is or should be transparent. Transparency is a virtue only in artificial instruments, organs in which no blood flows and whose intrinsic operation is not itself a portion of human life. In looking through a field-glass I do not wish to perceive the lenses nor to see rainbows about their rim; yet I should not wish the eye itself to lose its pigments and add no dyes to the bulks it discerns. The sense for colour is a vital endowment and an ingredient in human happiness; but no vitality is added by the intervention of further media which are not themselves living organs.