Fouillée supports the same thesis as a particular case of his general theory of _idées-forces_. The apparent present is a synthesis of real presents. Our primitive perception is of change, not of stability; we are conscious of transition. The static point of view must be completed by the dynamic. The complete separation of present and past is a mathematical fiction. The sum of transition which is a factor in appetite aids in forming the series. Time is a form of appetite; beneath the floating image there is a tendency to movement. A non-volitional being would have no representation of time: time is a form of appetition.[118] “It is probable,” says Mach, “that time sensation is connected with the organic _consumption_ necessarily associated with consciousness,—that we feel the _work of attention_ as time.... The fatiguing of the organ of consciousness goes on continually in waking hours, and the labor of attention increases just as continually. These sensations connected with greater expenditure of attention appear to us to happen later.”[119] Others again (Waitz, Guyau, and more particularly Ward) admit _temporal signs_ in imitation of Lotze’s “local signs.” Our successive acts of attention leave a series of residua, variable in intensity and precision; these “temporal signs” permit the conception of representations as successive, and no longer as simultaneous. “What is this distance that separates _A_ from _B_, _B_ from _C_, and so on?... It is probably that the residuum of which I have called a temporal sign; or, in other words, it is the movement of attention from _A_ to _B_.”[120] These extracts will suffice to show the character of the second theory, which seems to me the more acceptable. It is the more complete, inasmuch as it takes into consideration, not only the clear states, existing in consciousness, but the subconscious states also; it is not confined to intellectual elements alone (sensations and images), but recognises the necessary rôle of the active, motor elements.