Proof.- The order and connection of ideas is the same (II:vii.) as the order and connection of things, and vice versa the order and connection of things is the same (II:vi.Coroll. and II:vii.) as the order and connection of ideas. Wherefore, even as the order and connection of ideas in the mind takes place according to the order and association of modifications of the body (II:xviii.), so vice versa (III:ii.) the order and connection of modifications of the body takes place in accordance with the manner, in which thoughts and the ideas of things are arranged and associated in the mind. Q.E.D. PROP.II. If we remove a disturbance of the spirit, or emotion, from the thought of an external cause, and unite it to other thoughts, then will the love or hatred towards that external cause, and also the vacillations of spirit which arise from these emotions, be destroyed. Proof.- That, which constitutes the reality of love or hatred, is pleasure or pain, accompanied by the idea of an external cause (Def. of the Emotions:vi.,&vii.); wherefore, when this cause is removed, the reality of love or hatred is removed with it; therefore these emotions and those which arise therefrom are destroyed. Q.E.D. Prop.III. An emotion, which is a passion, ceases to be a passion, as soon as we form a clear and distinct idea thereof. Proof.- An emotion, which is a passion, is a confused idea (by the general Def. of the Emotions). If, therefore, we form a clear and distinct idea of a given emotion, that idea will only be distinguished from the emotion, in so far as it is referred to the mind only, by reason (II:xxi.,&Note); therefore (III:iii.), the emotion will cease to be a passion. Q.E.D. Corollary.- An emotion therefore becomes more under our control, and the mind is less passive in respect to it, in proportion as it is more known to us. Prop.IV. There is no modification of the body, whereof we cannot form some clear and distinct conception. Proof.- Properties which are common to all things can only be conceived adequately (II:xxxviii.); therefore (II:xii.and Lemma. ii. after II:xiii.) there is no modification of the body, whereof we cannot form some clear and distinct conception. Q.E.D. Corollary.- Hence it follows that there is no emotion, whereof we cannot form some clear and distinct conception. For an emotion is the idea of a modification of the body (by the general Def. of the Emotions), and must therefore (by the preceding Prop.) involve some clear and distinct conception.