To carry conviction to the farthest point, let us take this example of motion, and suppose a cube to be moved. Let us call its eight verticles A, B, C, D, E, F, G, H; they all move, and the collection of their motions, with those of the points which are between them, forms the whole motion. What is there common in the result of this concurrence of agents? Nothing, except juxtaposition in space, and the relation which they preserve by the equal velocity of the motion. But the motion of the vertex H is not the motion of the vertex A, as is evident if we consider that the vertex A may be cut off from the cube, and remain at rest without discontinuing or altering the motion of the vertex H; therefore, the two motions are things absolutely distinct. It is evident that the same holds true with respect to the other points; therefore the unity of the composite motion is purely factitious; what there is, in reality, is a multiplicity of substances, and of motions, without any other than a purely extrinsical connection, the relation of positions in space. Let us change the vertices into representations, and see what will be the result. Do they exist without any other connection than their co-existence? Then they do not form a thought, but only a collection of phenomena which may be considered as a _union_ of things, but not a thought; in that case the sum of all the representations will be similar to the sum of the motions; but it will produce no result in relation to the object which we are now examining. If we give these representations a point of union, that is, the relation under which they are perceived, we shall have a thought; but what has this act, which is _one_ and most simple, in common with, the totality of a number of points in motion? 86. If Kant had wished to present a more seductive example, he ought to have made use of a theory in mechanics, the application of which to the present case presents, if not more difficulty, at least a more deceitful appearance; I mean the resultant of a system of forces and their point of application. When several forces act upon a line, a plane, or a solid, they produce an effect equal to that one force alone, which is called the resultant: this force has a determinate direction and a point of application, as though it were simple or had not emanated from others; why cannot this be applied to thought? Why may not a thing, although it is simple, be the product of the concurrence of various agents? This example is more specious, because it presents the result of the composition concentrated in a point, but if we examine it well, we shall find that it proves nothing against us.