[Footnote 1:  By their mutual pressure representations are transformed into a mere tendency to represent, which again becomes actual representation when the arrest ceases.  The parts of a representation transformed into a tendency, and the residua remaining unobscured, are not pieces cut off, but the quantity denotes merely a degree of obscuration in the whole representation, or rather in the representation which actually takes place.]

As soon as a representation reaches the zero point of consciousness, or as soon as a new representation (sensation) comes in, the others begin at once to rise or sink.  The Mechanics seeks to investigate the laws of these movements of representations; but we may the more readily pass over its complicated calculations since their precise formulas can never more than very roughly represent the true state of the case, which simply rebels against precision.  The rock on which every immanent use of mathematics in psychology must strike, is the impossibility of exactly measuring one representation by another.  We may, indeed, declare one stronger than another on the basis of the immediate impression of feeling, but we cannot say how much stronger it is, nor with reason assert that it is twice or half as intense.  Herbart’s mathematical psychology was wrecked by this insurmountable difficulty.  The demand for exactness which it raised, but which it was unable to satisfy with the means at its disposal, has recently been renewed, and has led to assured results in psycho-physics, which works on a different basis and with ingenious methods of measurement.

Herbart endeavors, as we have seen, to deduce the various mental activities from the play of representations, Feeling and desire are not something beside representations, are not special faculties of the soul, but results of the relations of representations, changing states of representations arrested and working upward against hindrances.  A representation which has been forced out of consciousness persists as a tendency or effort to represent, and as such exerts a pressure on the conscious representations.  If a representation is suspended between counteracting forces a feeling results; desire is the rise of a representation in the face of hindrances, aversion is hesitation in sinking.  If the effort is accompanied by the idea that its goal is attainable, it is termed will.  The character of a man depends on the fact that definite masses of representations have become dominant, and by their strength and persistence hold opposing representations in check or suppress them.  The longer the dominant mass of representations exercises its power, the firmer becomes the habit of acting in a certain way, the more fixed the will.  Herbart’s intellectualistic denial of self-dependence to the practical capacities of the soul leads him logically to determinism.  Volition depends on insight, is determined by representations; freedom signifies nothing but the fact that the will