Page:Mind (Old Series) Volume 9.djvu/44

32 J. S. HALDANE. roundabout manner ; and the only escape from the difficulty lies in assuming that there is such a force. Let us consider more particularly how this force must act. When an earthworm fills up its burrow it is not performing an action unconnected with other events in its life. The filling up of the burrow is determined with reference to further ends, in the same sense as that in which the seizing of the apical portion of one of Darwin's triangles is deter- mined with reference to the end of filling up the burrow. And if this reasoning be followed out, it leads to the conclu- sion that all the actions of the worm can be regarded as determined more or less directly with reference to one comprehensive end the end, namely, of so influencing the surroundings as to cause them to direct to the animal a supply of energy sufficient to make up for what has been spent by it. From this it follows that the force whose existence we found it necessary to assume for the explanation of the movements of the worm in filling up its burrow that this force is subordinate to a force which connects generally the organism and its surroundings. Since the hypothesis of mechanisms within the organism fails us, it is only by assuming the existence of such a force that we can explain the determination with reference to the one comprehensive end mentioned above of all the actions of the animal. This force must be conceived as acting from the surroundings in all sorts of indirect ways on the parts of the organism, so as to cause them to act in their turn on the surroundings. In the same way a force is thought of as acting from the earth so as to cause a stone thrown into the air sooner or later to act on the earth by striking against it. Not only, however, do surroundings and organism successively act and react on one another ; but the organism, as we have seen, reacts on the surroundings in a certain particular manner in such a manner, namely, as to bring it about that the surroundings act again on the organism in transferring to it energy con- tained in food. In other words, the surroundings determine the organism to react upon them in a certain manner, but this manner of reaction is determined with reference to the organism itself. Now what is implied in saying that this manner of reaction is determined with reference to the organism itself, is that in being made to react on the sur- roundings the organism is determined by its own influence acting through the surroundings. The surroundings in acting on the organism are therefore at the same time acted on by it. The organism is thus no more determined by the sur-