Proof.- We do not regard a thing as absent, by reason of the emotion wherewith we conceive it, but by reason of the body, being affected by another emotion excluding the existence of the said thing (II:xvii.). Wherefore, the emotion, which is referred to the thing which we regard as absent, is not of a nature to overcome the rest of a man's activities and power (IV:vi.), but is, on the contrary, of a nature to be in some sort controlled by the emotions, which exclude the existence of its external cause (IV:ix.). But an emotion which springs from reason is necessarily referred to the common properties of things (see the def. of reason in II:xl.Note.ii.), which we always regard as present (for there can be nothing to exclude their present existence), and which we always conceive in the same manner (II:xxxviii.). Wherefore an emotion of this kind always remains the same; and consequently (V:Ax.i.) emotions, which are contrary thereto and are not kept going by their external causes, will be obliged to adapt themselves to it more and more, until they are no longer contrary to it; to this extent the emotion which springs from reason is more powerful. Q.E.D. Prop.VIII. An emotion is stronger in proportion to the number of simultaneous concurrent causes whereby it is aroused. Proof.- Many simultaneous causes are more powerful than a few (III:vii.): therefore (IV:v.), in proportion to the increased number of simultaneous causes whereby it is aroused, an emotion becomes stronger. Q.E.D. Note.- This proposition is also evident from V:Ax.ii. Prop.IX. An emotion, which is attributable to many and diverse causes which the mind regards as simultaneous with the emotion itself, is less hurtful, and we are less subject thereto and less affected towards each of its causes, than if it were a different and equally powerful emotion attributable to fewer causes or to a single cause. Proof-. An emotion is only bad or hurtful, in so far as it hinders the mind from being able to think (IV:xxvi., IV:xxvii.); therefore, an emotion, whereby the mind is determined to the contemplation of several things at once, is less hurtful than another equally powerful emotion, which so engrosses the mind in the single contemplation of a few objects or of one, that it is unable to think of anything else; this was our first point. Again, as the mind's essence, in other words, its power (III:vii.), consists solely in thought (II:xi.), the mind is less passive in respect to an emotion, which causes it to think of several things at once, than in regard to an equally strong emotion, which keeps it engrossed in the contemplation of a few or of a single object: this was our second point. Lastly, this emotion (III:xlviii.), in so far as it is attributable to several causes, is less powerful in regard to each of them. Q.E.D.