Therefore, every man, solely by the laws of his nature, desires the one, and shrinks from the other, &c. Q.E.D.
PROP. XX. The more every man endeavours, and is able to seek what is useful to him--in other words, to preserve his own being--the more is he endowed with virtue; on the contrary, in proportion as a man neglects to seek what is useful to him, that is, to preserve his own being, he is wanting in power.
Proof.--Virtue is human power, which is defined solely by man's essence (IV. Def. viii.), that is, which is defined solely by the endeavour made by man to persist in his own being.
Wherefore, the more a man endeavours, and is able to preserve his own being, the more is he endowed with virtue, and, consequently (III. iv. and vi.), in so far as a man neglects to preserve his own being, he is wanting in power. Q.E.D.
Note.--No one, therefore, neglects seeking his own good, or preserving his own being, unless he be overcome by causes external and foreign to his nature. No one, I say, from the necessity of his own nature, or otherwise than under compulsion from external causes, shrinks from food, or kills himself: which latter may be done in a variety of ways. A man, for instance, kills himself under the compulsion of another man, who twists round his right hand, wherewith he happened to have taken up a sword, and forces him to turn the blade against his own heart; or, again, he may be compelled, like Seneca, by a tyrant's command, to open his own veins--that is, to escape a greater evil by incurring, a lesser; or, lastly, latent external causes may so disorder his imagination, and so affect his body, that it may assume a nature contrary to its former one, and whereof the idea cannot exist in the mind (III. x.) But that a man, from the necessity of his own nature, should endeavour to become non--existent, is as impossible as that something should be made out of nothing, as everyone will see for himself, after a little reflection.
PROP. XXI. No one can desire to be blessed, to act rightly, and to live rightly, without at the same time wishing to be, act, and to live--in other words, to actually exist.
Proof.--The proof of this proposition, or rather the proposition itself, is self--evident, and is also plain from the definition of desire. For the desire of living, acting, &c., blessedly or rightly, is (Def. of the Emotions, i.) the essence of man--that is (III. vii.), the endeavour made by everyone to preserve his own being. Therefore, no one can desire, &c.
Q.E.D.
PROP. XXII. No virtue can be conceived as prior to this endeavour to preserve one's own being.
Proof.--The effort for self--preservation is the essence of a thing (III. vii.); therefore, if any virtue could be conceived as prior thereto, the essence of a thing would have to be conceived as prior to itself, which is obviously absurd.
Therefore no virtue, &c. Q.E.D.
Corollary.--The effort for self--preservation is the first and only foundation of virtue. For prior to this principle nothing can be conceived, and without it no virtue can be conceived.
PROP. XXIII. Man, in so far as he is determined to a particular action because he has inadequate ideas, cannot be absolutely said to act in obedience to virtue; he can only be so described, in so far as he is determined for the action because he understands.
Proof.--In so far as a man is determined to an action through having inadequate ideas, he is passive (III. i.), that is (III.
Deff. i., and iii.), he does something, which cannot be perceived solely through his essence, that is (by IV. Def. viii.), which does not follow from his virtue. But, in so far as he is determined for an action because he understands, he is active; that is, he does something, which is perceived through his essence alone, or which adequately follows from his virtue.
Q.E.D.
PROP. XXIV. To act absolutely in obedience to virtue is in us the same thing as to act, to live, or to preserve one's being (these three terms are identical in meaning) in accordance with the dictates of reason on the basis of seeking what is useful to one's self.
Proof.--To act absolutely in obedience to virtue is nothing else but to act according to the laws of one's own nature. But we only act, in so far as we understand (III. iii.): therefore to act in obedience to virtue is in us nothing else but to act, to live, or to preserve one's being in obedience to reason, and that on the basis of seeking what is useful for us (IV. xxii.
Coroll.). Q.E.D.
PROP. XXV. No one wishes to preserve his being for the sake of anything else.
Proof.--The endeavour, wherewith everything endeavours to persist in its being, is defined solely by the essence of the thing itself (III. vii.); from this alone, and not from the essence of anything else, it necessarily follows (III. vi.) that everyone endeavours to preserve his being. Moreover, this proposition is plain from IV. xxii. Coroll., for if a man should endeavour to preserve his being for the sake of anything else, the last--named thing would obviously be the basis of virtue, which, by the foregoing corollary, is absurd. Therefore no one, &c. Q.E.D.
PROP. XXVI. Whatsoever we endeavour in obedience to reason is nothing further than to understand; neither does the mind, in so far as it makes use of reason, judge anything to be useful to it, save such things as are conducive to understanding.
Proof.--The effort for self--preservation is nothing else but the essence of the thing in question (III. vii.), which, in so far as it exists such as it is, is conceived to have force for continuing in existence (III. vi.) and doing such things as necessarily follow from its given nature (see the Def. of Appetite, III. ix. note). But the essence of reason is nought else but our mind, in so far as it clearly and distinctly understands (see the definition in II. xl. note. ii.); therefore (II. xl.) whatsoever we endeavour in obedience to reason is nothing else but to understand. Again, since this effort of the mind wherewith the mind endeavours, in so far as it reasons, to preserve its own being is nothing else but understanding; this effort at understanding is (IV. xxii. Coroll.) the first and single basis of virtue, nor shall we endeavour to understand things for the sake of any ulterior object (IV. xxv.); on the other hand, the mind, in so far as it reasons, will not be able to conceive any good for itself, save such things as are conducive to understanding.
PROP. XXVII. We know nothing to be certainly good or evil, save such things as really conduce to understanding, or such as are able to hinder us from understanding.
Proof.--The mind, in so far as it reasons, desires nothing beyond understanding, and judges nothing to be useful to itself, save such things as conduce to understanding (by the foregoing Prop.). But the mind (II. xli., xliii. and note) cannot possess certainty concerning anything, except in so far as it has adequate ideas, or (what by II. xl. note, is the same thing) in so far as it reasons. Therefore we know nothing to be good or evil save such things as really conduce, &c. Q.E.D.
PROP. XXVIII. The mind's highest good is the knowledge of God, and the mind's highest virtue is to know God.
Proof.--The mind is not capable of understanding anything higher than God, that is (I. Def. vi.), than a Being absolutely infinite, and without which (I. xv.) nothing can either be or be conceived; therefore (IV. xxvi. and xxvii.), the mind's highest utility or (IV. Def. i.) good is the knowledge of God. Again, the mind is active, only in so far as it understands, and only to the same extent can it be said absolutely to act virtuously. The mind's absolute virtue is therefore to understand. Now, as we have already shown, the highest that the mind can understand is God; therefore the highest virtue of the mind is to understand or to know God. Q.E.D.
PROP. XXIX. No individual thing, which is entirely different from our own nature, can help or check our power of activity, and absolutely nothing can do us good or harm, unless it has something in common with our nature.
Proof.--The power of every individual thing, and consequently the power of man, whereby he exists and operates, can only be determined by an individual thing (I. xxviii.), whose nature (II.
vi.) must be understood through the same nature as that, through which human nature is conceived. Therefore our power of activity, however it be conceived, can be determined and consequently helped or hindered by the power of any other individual thing, which has something in common with us, but not by the power of anything, of which the nature is entirely different from our own; and since we call good or evil that which is the cause of pleasure or pain (IV. viii.), that is (III.
xi. note), which increases or diminishes, helps or hinders, our power of activity; therefore, that which is entirely different from our nature can neither be to us good nor bad. Q.E.D.
PROP. XXX. A thing cannot be bad for us through the quality which it has in common with our nature, but it is bad for us in so far as it is contrary to our nature.
Proof.--We call a thing bad when it is the cause of pain (IV.
viii.), that is (by the Def., which see in III. xi. note), when it diminishes or checks our power of action. Therefore, if anything were bad for us through that quality which it has in common with our nature, it would be able itself to diminish or check that which it has in common with our nature, which (III.
iv.) is absurd. Wherefore nothing can be bad for us through that quality which it has in common with us, but, on the other hand, in so far as it is bad for us, that is (as we have just shown), in so far as it can diminish or check our power of action, it is contrary to our nature.
Q.E.D.
PROP. XXXI. In so far as a thing is in harmony with our nature, it is necessarily good.
Proof.--In so far as a thing is in harmony with our nature, it cannot be bad for it. It will therefore necessarily be either good or indifferent. If it be assumed that it be neither good nor bad, nothing will follow from its nature (IV. Def. i.), which tends to the preservation of our nature, that is (by the hypothesis), which tends to the preservation of the thing itself; but this (III. vi.) is absurd; therefore, in so far as a thing is in harmony with our nature, it is necessarily good. Q.E.D.
Corollary.--Hence it follows, that, in proportion as a thing is in harmony with our nature, so is it more useful or better for us, and vice versa, in proportion as a thing is more useful for us, so is it more in harmony with our nature. For, in so far as it is not in harmony with our nature, it will necessarily be different therefrom or contrary thereto. If different, it can neither be good nor bad (IV. xxix.); if contrary, it will be contrary to that which is in harmony with our nature, that is, contrary to what is good--in short, bad. Nothing, therefore, can be good, except in so far as it is in harmony with our nature; and hence a thing is useful, in proportion as it is in harmony with our nature, and vice versa. Q.E.D.
PROP. XXXII. In so far as men are a prey to passion, they cannot, in that respect, be said to be naturally in harmony.
Proof.--Things, which are said to be in harmony naturally, are understood to agree in power (III. vii.), not in want of power or negation, and consequently not in passion (III. iii. note); wherefore men, in so far as they are a prey to their passions, cannot be said to be naturally in harmony. Q.E.D.
Note.--This is also self--evident; for, if we say that white and black only agree in the fact that neither is red, we absolutely affirm that the do not agree in any respect. So, if we say that a man and a stone only agree in the fact that both are finite--wanting in power, not existing by the necessity of their own nature, or, lastly, indefinitely surpassed by the power of external causes--we should certainly affirm that a man and a stone are in no respect alike; therefore, things which agree only in negation, or in qualities which neither possess, really agree in no respect.
PROP. XXXIII. Men can differ in nature, in so far as they are assailed by those emotions, which are passions, or passive states; and to this extent one and the same man is variable and inconstant.
Proof.--The nature or essence of the emotions cannot be explained solely through our essence or nature (III. Deff. i., ii.), but it must be defined by the power, that is (III. vii.), by the nature of external causes in comparison with our own; hence it follows, that there are as many kinds of each emotion as there are external objects whereby we are affected (III. lvi.), and that men may be differently affected by one and the same object (III. li.), and to this extent differ in nature; lastly, that one and the same man may be differently affected towards the same object, and may therefore be variable and inconstant. Q.E.D.
PROP. XXXIV. In so far as men are assailed by emotions which are passions, they can be contrary one to another.
Proof.--A man, for instance Peter, can be the cause of Paul's feeling pain, because he (Peter) possesses something similar to that which Paul hates (III. xvi.), or because Peter has sole possession of a thing which Paul also loves (III. xxxii. and note), or for other causes (of which the chief are enumerated in III. lv. note); it may therefore happen that Paul should hate Peter (Def. of Emotions, vii.), consequently it may easily happen also, that Peter should hate Paul in return, and that each should endeavour to do the other an injury, (III. xxxix.), that is (IV.
xxx.), that they should be contrary one to another. But the emotion of pain is always a passion or passive state (III. lix.); hence men, in so far as they are assailed by emotions which are passions, can be contrary one to another. Q.E.D.
Note.--I said that Paul may hate Peter, because he conceives that Peter possesses something which he (Paul) also loves; from this it seems, at first sight, to follow, that these two men, through both loving the same thing, and, consequently, through agreement of their respective natures, stand in one another's way; if this were so, Props. xxx. and xxxi. of this part would be untrue. But if we give the matter our unbiased attention, we shall see that the discrepancy vanishes. For the two men are not in one another's way in virtue of the agreement of their natures, that is, through both loving the same thing, but in virtue of one differing from the other. For, in so far as each loves the same thing, the love of each is fostered thereby (III. xxxi.), that is (Def. of the Emotions, vi.) the pleasure of each is fostered thereby. Wherefore it is far from being the case, that they are at variance through both loving the same thing, and through the agreement in their natures. The cause for their opposition lies, as I have said, solely in the fact that they are assumed to differ. For we assume that Peter has the idea of the loved object as already in his possession, while Paul has the idea of the loved object as lost. Hence the one man will be affected with pleasure, the other will be affected with pain, and thus they will be at variance one with another. We can easily show in like manner, that all other causes of hatred depend solely on differences, and not on the agreement between men's natures.
PROP. XXXV. In so far only as men live in obedience to reason, do they always necessarily agree in nature.
Proof.--In so far as men are assailed by emotions that are passions, they can be different in nature (IV. xxxiii.), and at variance one with another. But men are only said to be active, in so far as they act in obedience to reason (III. iii.); therefore, what so ever follows from human nature in so far as it is defined by reason must (III. Def. ii.) be understood solely through human nature as its proximate cause. But, since every man by the laws of his nature desires that which he deems good, and endeavours to remove that which he deems bad (IV. xix.); and further, since that which we, in accordance with reason, deem good or bad, necessarily is good or bad (II. xli.); it follows that men, in so far as they live in obedience to reason, necessarily do only such things as are necessarily good for human nature, and consequently for each individual man (IV. xxxi.
Coroll.); in other words, such things as are in harmony with each man's nature. Therefore, men in so far as they live in obedience to reason, necessarily live always in harmony one with another. Q.E.D.
Corollary I.--There is no individual thing in nature, which is more useful to man, than a man who lives in obedience to reason.
For that thing is to man most useful, which is most in harmony with his nature (IV. xxxi. Coroll.); that is, obviously, man.
But man acts absolutely according to the laws of his nature, when he lives in obedience to reason (III. Def. ii.), and to this extent only is always necessarily in harmony with the nature of another man (by the last Prop.); wherefore among individual things nothing is more useful to man, than a man who lives in obedience to reason. Q.E.D.
Corollary II.--As every man seeks most that which is useful to him, so are men most useful one to another. For the more a man seeks what is useful to him and endeavours to preserve himself, the more is he endowed with virtue (IV. xx.), or, what is the same thing (IV. Def. viii.), the more is he endowed with power to act according to the laws of his own nature, that is to live in obedience to reason. But men are most in natural harmony, when they live in obedience to reason (by the last Prop.); therefore (by the foregoing Coroll.) men will be most useful one to another, when each seeks most that which is useful to him.
Q.E.D.
Note.--What we have just shown is attested by experience so conspicuously, that it is in the mouth of nearly everyone: "Man is to man a God." Yet it rarely happens that men live in obedience to reason, for things are so ordered among them, that they are generally envious and troublesome one to another.
Nevertheless they are scarcely able to lead a solitary life, so that the definition of man as a social animal has met with general assent; in fact, men do derive from social life much more convenience than injury. Let satirists then laugh their fill at human affairs, let theologians rail, and let misanthropes praise to their utmost the life of untutored rusticity, let them heap contempt on men and praises on beasts; when all is said, they will find that men can provide for their wants much more easily by mutual help, and that only by uniting their forces can they escape from the dangers that on every side beset them: not to say how much more excellent and worthy of our knowledge it is, to study the actions of men than the actions of beasts. But I will treat of this more at length elsewhere.
PROP. XXXVI. The highest good of those who follow virtue is common to all, and therefore all can equally rejoice therein.