b. From these external perceptions of objects presently existing, with which we here began, the affections, the internal perceptions, which give the criteria for practical life are however distinguished; they are of two kinds, either pleasant or unpleasant. That is to say, they have as their content pleasure or satisfaction, and pain: the first, as that which peculiarly belongs to the perceiver, is the positive; but pain, as something alien to him, is the negative. It is these sensuous perceptions which determine action; they are the material from which general conceptions regarding what causes me pain or pleasure are formed; as being permanent they are therefore again conceptions, and opinion is again this reference of conception to perception, according to which I pass judgment on objects—affections, desires, and so on.[152] It is by this opinion, therefore, that the decision to do or to avoid anything is arrived at. This constitutes the whole Canon of Epicurus, the universal standard of truth; it is so simple that nothing can well be simpler, and yet it is very abstract. It consists of ordinary psychological conceptions which are correct on the whole, but quite superficial; it is the mechanical view of conception having respect to the first beginnings of observation. But beyond this there lies another and quite different sphere, a field that contains determinations in themselves; and these are the criteria by which the statements of Epicurus must be judged. Nowadays even Sceptics are fond of speaking of facts of consciousness; this sort of talk goes no further than the Epicurean Canon. 2. METAPHYSICS. In the second place, Epicurus enters on a metaphysical explanation of how we are related to the object; for sensuous perception and outside impressions he unhesitatingly regards as our relation to external things, so that he places the conceptions in me, the objects outside of me. In raising the question of how we come by our conceptions, there lies a double question: on the one hand, since sense-perceptions are not like conceptions, but require an external object, what is the objective manner in which the images of external things enter into us? On the other hand, it may be asked how conceptions of such things as are not matter of perception arise in us; this seems to be an activity of thought, which derives conceptions such as these from other conceptions; we shall, however, see presently (pp. 287, 288) and more in detail, how the soul, which is here related to the object in independent activity, arrives at such a point.