The disparity is this: thought is a simple act in itself, whilst the resultant of the forces is so only in its relation to the effect experienced, which is all that comes under our calculation. If two forces are applied at the two extremities of an inflexible right line the effect will be the same as though we applied one force equal to the sum of them both at one point of the line, at a distance from either extremity inversely proportioned to the value of the first forces. But the unity of this effect depends on the cohesion of the parts, which, not permitting isolated motions, must make the force act on a single point; but the component forces do not cease to be distinct and separate, so that at the moment the cohesion should cease, the respective parts would each feel the action of the force corresponding to it, and move in the direction and with the velocity which the force impresses on them. If, while the cohesion lasts, it were possible to give each of the component forces the consciousness of its action, there would be two consciousnesses really distinct, which could never form one common consciousness, and could only be united in the production of an effect. If the point of their application should have the consciousness of the action which it experiences, it might have a consciousness similar to that of the action of one force, equal to the sum of the components, if it did not know the manner in which their action is transmitted to it; but from the moment that it becomes conscious of their respective action, it would know that the result is owing to the impossibility of each of them producing its effect in an isolated manner. If, therefore, we compare the thinking subject to this point of application of the forces, we must attribute to this subject the consciousness of the origin of the representations which concur in the production of the whole effect.