But, in order that this power of the mind over the emotions may be better understood, it should be specially observed that the emotions are called by us strong, when we compare the emotion of one man with the emotion of another, and see that one man is more troubled than another by the same emotion; or when we are comparing the various emotions of the same man one with another, and find that he is more affected or stirred by one emotion than by another. For the strength of every emotion is defined by a comparison of our own power with the power of an external cause. Now the power of the mind is defined by knowledge only, and its infirmity or passion is defined by the privation of knowledge only: it therefore follows, that that mind is most passive, whose greatest part is made up of inadequate ideas, so that it may be characterized more readily by its passive states than by its activities: on the other hand, that mind is most active, whose greatest part is made up of adequate ideas, so that, although it may contain as many inadequate ideas as the former mind, it may yet be more easily characterized by ideas attributable to human virtue, than by ideas which tell of human infirmity. Again, it must be observed, that spiritual unhealthiness; and misfortunes can generally be traced to excessive love for something which is subject to many variations, and which we can never become masters of. For no one is solicitous or anxious about anything, unless he loves it; neither do wrongs, suspicions, enmities, &c. arise, except in regard to things whereof no one can be really master.
We may thus readily conceive the power which clear and distinct knowledge, and especially that third kind of knowledge (II:xlvii.Note), founded on the actual knowledge of God, possesses over the emotions: if it does not absolutely destroy them, in so far as they are passions (V:iii. and V:iv.Note); at any rate, it causes them to occupy a very small part of the mind (V:xiv.). Further, it begets a love towards a thing immutable and eternal (V:xv.), whereof we may really enter into possession (II:xlv.); neither can it be defiled with those faults which are inherent in ordinary love; but it may grow from strength to strength, and may engross the greater part of the mind, and deeply penetrate it. And now I have finished with all that concerns this present life: for, as I said in the beginning of this note, I have briefly described all the remedies against the emotions. And this everyone may readily have seen for himself, if he has attended to what is advanced in the present note, and also to the definitions of the mind and its emotions, and, lastly, to Propositions III:i. and III:iii. It is now, therefore, time to pass on to those matters, which appertain to the duration of the mind, without relation to the body.
Prop. XXI. The mind can only imagine anything, or remember what is past, while the body endures.
Proof.- The mind does not express the actual existence of its body, nor does it imagine the modifications of the body as actual, except while the body endures (II:viii.Coroll.); and, consequently (II:xxvi.), it does not imagine any body as actually existing, except while its own body endures. Thus it cannot imagine anything (for definition of Imagination, see II:xvii.Note), or remember things past, except while the body endures (see definition of Memory, II:xviii.Note). Q.E.D.
Prop. XXII. Nevertheless in God there is necessarily an idea, which expresses the essence of this or that human body under the form of eternity.
Proof.- God is the cause, not only of the existence of this or that human body, but also of its essence (I:xxv.). This essence, therefore, must necessarily be conceived through the very essence of God (I:Ax.iv.), and be thus conceived by a certain eternal necessity (I:xvi.); and this conception. must necessarily exist in God (II:iii.). Q.E.D.
Prop. XXIII. The human mind cannot be absolutely destroyed with the body, but there remains of it something which is eternal.
Proof.- There is necessarily in God a concept or idea, which expresses the essence of the human body (last Prop.), which, therefore, is necessarily something appertaining to the essence of the human mind (II:xiii.). But we have not assigned to the human mind any, duration, definable by time, except in so far as it expresses the actual existence of the body, which is explained through duration, and may be defined by time - that is (II:viii.Coroll.), we do not assign to it duration, except while the body endures. Yet, as there is something, notwithstanding, which is conceived by a certain eternal necessity through the very essence of God (last Prop.); this something, which appertains to the essence of the mind, will necessarily be eternal. Q.E.D.
Note.- This idea, which expresses the essence of the body under the form of eternity, is, as we have said, a certain mode of thinking, which belongs to the essence of the mind, and is necessarily eternal. Yet it is not possible that we should remember that we existed before our body, for our body can bear no trace of such existence, neither can eternity be defined in terms of time, or have any relation to time. But, notwithstanding, we feel and know that we are eternal. For the mind feels those things that it conceives by understanding, no less than those things that it remembers. For the eyes of the mind, whereby it sees and observes things, are none other than proofs.
Thus, although we do not remember that we existed before the body, yet we feel that our mind, in so far as it involves the essence of the body, under the form of eternity, is eternal, and that thus its existence cannot be defined in terms of time, or explained through duration. Thus our mind can only be said to endure, and its existence can only be defined by a fixed time, in so far as it involves the actual existence of the body. Thus far only has it the power of determining the existence of things by time, and conceiving them under the category of duration.
