If the ideas we have been considering in respect to organic life are true, we cannot but feel that, to a certain extent, our former thoughts have been inverted. We have long been accustomed to hear it assumed, that the organic world is distinguished at once by a special eminence over the rest of nature, and by a special mystery; so that it is that which of all things we can least hope to understand. It seems to me, however, that this idea is the very opposite of the truth. So far from being less comprehensible than the rest of nature, the organic world appears rather to be that very part of it which we may most truly be said to know: the inorganic world with its deep-hidden forces is the mystery. For it must not be forgotten that, in discussing organic life, we pre-suppose the chemical affinities; and these being taken as our postulates, the phenomena of the organic world are of the kind which we best understand. As based on an opposition, by other forces, to those chemical affinities, and as displaying powers due to the force thus stored up, life presents to us no mystery. Almost we might say that it exhibits to us, under this aspect, the one thing in respect to the natural forces that we may be said to comprehend : the production of a tension and its results.