I heartily agree with you so far as this, that intellectual relations will not sustain friendship for very long, unless there is also some basis of feeling to sustain it. And still there is a certain reality in the friendships of the intellect whilst they last, and they are remembered gratefully for their profit when in the course of nature they have ceased. We may wisely contract them, and blamelessly dissolve them when the occasion that created them has gone by. They are like business partnerships, contracted from motives of interest, and requiring integrity above all things, with mutual respect and consideration, yet not necessarily either affection or the semblance of it. Since the motive of the intellectual existence is the desire to ascertain and communicate truth, a sort of positive and negative electricity immediately establishes itself between those who want to know and those who desire to communicate their knowledge; and the connection is mutually agreeable until these two desires are satisfied. When this happens, the connection naturally ceases; but the memory of it usually leaves a permanent feeling of good-will, and a permanent disposition to render services of the same order. This, in brief, is the whole philosophy of the subject; but it may be observed farther, that the purely intellectual intercourse which often goes by the name of friendship affords excellent opportunities for the formation of real friendship, since it cannot be long continued without revealing much of the whole nature of the associates.