This theory of pain and pleasure, as the synonyms of the practical positive and negative, helps to put an end to a long series of questions arising in connection with such concepts. Above all, the dispute as to whether pleasure be positive or negative will appear to be unfounded, and, therefore, whether pain have a positive or a negative value, or, finally, whether both be negative: unfounded, since "pleasure" means "positive" and "pain" "negative." At the most, it may be admitted that pain has also a positivity, which is however nothing but the positivity of the negative, that is the real existence of the negative pole.--The theory that man always proposes to himself pleasure as an end is, on the contrary, not only not unfounded, but of such evident truth as not to require enunciation, much less efforts to prove it. If pleasure be nothing but activity, it is natural that man should have no other end save pleasure, that is, activity, life itself. The correction that has been suggested by others, to the effect that man wills, not indeed pleasure, but activity, of which the outcome is pleasure, has but slight exactitude, for the two terms are not distinguishable, and the result is not separable from the activity; the pleasure of travelling is not separable from travelling. That polemic has value at the most against empiricism, which limits pleasure to an arbitrarily determined group of pleasurable facts, that is to say, circumscribes activity to certain particular manifestations of activity, collected in groups or classes, and substituted for the universal concept. Finally, by means of the identification of pleasure and pain with good and evil in general which we have given, all disputes as to the concept of _happiness_ disappear, as to whether it be or be not distinct from that of the good action, practically coherent, and if man propose to himself _happiness_ as an end. "Happiness" is equal to "pleasure," and "pleasure" is equal to "activity." To will the good (that is, to will well and energetically), and to be happy, are the same. The objection raised by some, that man does not will happiness, but a certain happiness, that he does not will pleasure, but a certain pleasure, not the good, but a certain good, is valid; but this only amounts to distinguishing volitional man in the act, from the theory of the will, constructed by the philosopher. If Tizio wishes at this moment to go to bed and Caio to take a moonlight walk, bed and walk are the affairs of Tizio and of Caio; for the philosopher there is no Tizio, no Caio, but man in universal; there is neither bed nor moon, but pleasure and the good. [Sidenote: _Empirical concepts relating to good and evil._]