Proposition 59. To all the actions, whereto we are determined by emotion wherein the mind is passive; we can be determined without emotion by reason. Proof: To act rationally, is nothing else (3.3 and Def. 2) but to perform those actions, which follow from the necessity, of our nature considered in itself alone.
But pain is bad, in so far as it diminishes or checks the power of action (4.41).
Wherefore we cannot by pain be determined to any action, which we should be unable to perform under the guidance of reason.
Again, pleasure is bad only in so far as it hinders a man's capability for action (4.41. 43).
Therefore to this extent we could not be determined by it to any action, which we could not perform under the guidance of reason.
Lastly, pleasure, in so far as it is good, is in harmony with reason (for it consists in the fact that a man's capability for action is increased or aided);
nor is the mind passive therein, except in so far as a man's power of action is not increased to the extent of affording him an adequate conception of himself and his actions (3.3., and note).
Wherefore, if a man who is pleasurably affected be brought to such a state of perfection, that he gains an adequate conception of himself and his own actions, he will be equally, nay more, capable of those actions, to which he is determined by emotion wherein the mind is passive.
But all emotions are attributable to pleasure, to pain, or to desire (Def. of the Emotions, 4 explanation) and desire (Def. of the Emotions, 1) is nothing else but the attempt to act.
Therefore, to all actions, etc. Q.E.D.
Another Proof: A given action is called bad, in so far as it arises from one being affected by hatred or any evil emotion.
But no action, considered in itself alone, is either good or bad (as we pointed out in the preface to Pt. 4), one and the same action being sometimes good, sometimes bad.
Wherefore to the action which is sometimes bad, or arises from some evil emotion, we may be led by reason (4.19). Q.E.D.
Note: An example will put this point in a clearer light.
The action of striking, in so far as it is considered physically, and in so far as we merely look to the fact that a man raises his arm, clenches his fist, and moves his whole arm violently downwards, is a virtue or excellence which is conceived as proper to the structure of the human body.
If, then, a man, moved by anger or hatred, is led to clench his fist or to move his arm, this result takes place (as we showed in Pt. 2), because one and the same action can be associated with various mental images of things.
Therefore we may be determined to the performance of one and the same action by confused ideas, or by clear and distinct ideas.
Hence it is evident that every desire which springs from emotion, wherein the mind is passive, would become useless, if men could be guided by reason.
Let us now see why desire which arises from emotion, wherein the mind is passive, is called by us blind.
Proposition 60. Desire arising from a pleasure or pain, that is not attributable to the whole body, but only to one or certain parts thereof, is without utility in respect to a man as a whole. Proof: Let it be assumed, for instance, that A, a part of a body, is so strengthened by some external cause, that it prevails over the remaining parts (4.6).
This part will not endeavour to do away with its own powers, in order that the other parts of the body may perform its office; for this it would be necessary for it to have a force or power of doing away with its own powers, which (3.6.) is absurd.
The said part, and, consequently, the mind also, will endeavour to preserve its condition.
Wherefore desire arising from a pleasure of the kind aforesaid has no utility in reference to a man as a whole.
If it be assumed, on the other hand, that the part, A, be checked so that the remaining parts prevail, it may be proved in the same manner that desire arising from pain has no utility in respect to a man as a whole. Q.E.D.
Note: As pleasure is generally (4.44. note) attributed to one part of the body, we generally desire to preserve our being with out taking into consideration our health as a whole:
to which it may be added, that the desires which have most hold over us (4.9) take account of the present and not of the future.
Proposition 61. Desire which springs from reason cannot be excessive. Proof: Desire (Def. of the Emotions, 1) considered absolutely is the actual essence of man, in so far as it is conceived as in any way determined to a particular activity by some given modification of itself.
Hence desire, which arises from reason, that is (3.3), which is engendered in us in so far as we act, is the actual essence or nature of man, in so far as it is conceived as determined to such activities as are adequately conceived through man's essence only (3 Def. 2).
If such desire could be excessive, human nature considered in itself alone would be able to exceed itself, or would be able to do more than it can, a manifest contradiction.
Therefore, such desire cannot be excessive. Q.E.D.
Proposition 62. In so far as the mind conceives a thing under the dictates of reason, it is affected equally, whether the idea be of a thing future, past, or present. Proof: Whatsoever the mind conceives under the guidance of reason, it conceives under the form of eternity or necessity (2.44. Coroll. 2), and is therefore affected with the same certitude (2.43. and note).
Wherefore, whether the thing be present, past, or future, the mind conceives it under the same necessity and is affected with the same certitude;
and whether the idea be of something present, past, or future, it will in all cases be equally true (2.41);
that is, it will always possess the same properties of an adequate idea (2. Def. 4);
Therefore, in so far as the mind conceives things under the dictates of reason, it is affected in the same manner, whether the idea be of a thing future, past, or present. Q.E.D.
Note: If we could possess an adequate knowledge of the duration of things, and could determine by reason their periods of existence, we should contemplate things future with the same emotion as things present;
and the mind would desire as though it were present the good which it conceived as future;
Consequently it would necessarily neglect a lesser good in the present for the sake of a greater good in the future, and would in no wise desire that which is good in the present but a source of evil in the future, as we shall presently show.
However, we can have but a very inadequate knowledge of the duration of things (2.31.)
and the periods of their existence (2.44. note.) we can only determine by imagination, which is not so powerfully affected by the future as by the present.
Hence such true knowledge of good and evil as we possess is merely abstract or general, and the judgment which we pass on the order of things and the connection of causes, with a view to determining what is good or bad for us in the present, is rather imaginary than real.
Therefore it is nothing wonderful, if the desire arising from such knowledge of good and evil, in so far as it looks on into the future, be more readily checked than the desire of things which are agreeable at the present time. (Cf. 4.16.)
Proposition 63. He who is led by fear, and does good in order to escape evil, is not led by reason. Proof: All the emotions which are attributable to the mind as active, or in other words to reason, are emotions of pleasure and desire (3.59).
Therefore, he who is led by fear, and does good in order to escape evil, is not led by reason.
Note: Superstitions persons, who know better how to rail at vice than how to teach virtue, and who strive not to guide men by reason, but so to restrain them that they would rather escape evil than love virtue, have no other aim but to make others as wretched as themselves; wherefore it is nothing wonderful, if they be generally troublesome and odious to their fellow-men. Corollary: Under desire which springs from reason, we seek good directly, and shun evil indirectly. Proof: Desire which springs from reason can only spring from a pleasurable emotion, wherein the mind is not passive (3.59), in other words, from a pleasure which cannot be excessive (4.61.), and not from pain;
Wherefore this desire springs from the knowledge of good, not of evil (4.8).
Hence under the guidance of reason we seek good directly and only by implication shun evil. Q.E.D.
Note: This Corollary may be illustrated by the example of a sick and a healthy man.
The sick man through fear of death eats what he naturally shrinks from, but the healthy man takes pleasure in his food, and thus gets a better enjoyment out of life, than if he were in fear of death, and desired directly to avoid it.
So a judge, who condemns a criminal to death, not from hatred or anger but from love of the public well—being, is guided solely by reason.
Proposition 64. The knowledge of evil is an inadequate knowledge. Proof: The knowledge of evil (4.8) is pain, in so far as we are conscious thereof.
Pain is the transition to a lesser perfection (Def. of the Emotions, 3) and therefore cannot be understood through man's nature (3.6. and 3.7).
Therefore it is a passive state (3. Def. 2) which (3.3.) depends on inadequate ideas.
Consequently, the knowledge thereof (2.29), namely, the knowledge of evil, is inadequate. Q.E.D.
Corollary: It follows that, if the human mind possessed only adequate ideas, it would form no conception of evil. Proposition 65. Under the guidance of reason we should pursue the greater of two goods and the lesser of two evils. Proof: A good which prevents our enjoyment of a greater good is in reality an evil.
For we apply the terms good and bad to things, in so far as we compare them one with another (see preface to this Part).
Therefore, evil is in reality a lesser good.
Hence under the guidance of reason we seek or pursue only the greater good and the lesser evil. Q.E.D.
Corollary: We may, under the guidance of reason, pursue the lesser evil as though it were the greater good, and we may shun the lesser good, which would be the cause of the greater evil.
For the evil, which is here called the lesser, is really good, and the lesser good is really evil, wherefore we may seek the former and shun the latter. Q.E.D.
Proposition 66. We may, under the guidance of reason, seek a greater good in the future in preference to a lesser good in the present, and we may seek a lesser evil in the present in preference to a greater evil in the future.
 "Maltim praesens minus prae majori futuro." (Van Vloten). Bruder reads: "Malum praesens minus, quod causa est faturi alicujus mali." The last word of the latter is an obvious misprint, and is corrected by the Dutch translator into "majoris boni." (Pollock, p. 268, note.)
Proof: If the mind could have an adequate knowledge of things future, it would be affected towards what is future in the same way as towards what is present (4.62).
Wherefore, looking merely to reason, as in this proposition we are assumed to do, there is no difference, whether the greater good or evil be assumed as present, or assumed as future.
Hence (4.65) we may seek a greater good in the future in preference to a lesser good in the present, etc. Q.E.D.
Corollary: We may, under the guidance of reason, seek a lesser evil in the present, because it is the cause of a greater good in the future, and we may shun a lesser good in the present, because it is the cause of a greater evil in the future.
This Corollary is related to the foregoing Proposition as the Corollary to IV. lxv. is related to the said 4.65.
Note: If these statements be compared with what we have pointed out concerning the strength of the emotions in this Part up to Prop. 18.
We shall readily see the difference between a man, who is led solely by emotion or opinion, and a man, who is led by reason.
The former, whether will or no, performs actions whereof he is utterly ignorant;
The latter is his own master and only performs such actions, as he knows are of primary importance in life, and therefore chiefly desires;
Wherefore I call the former a slave, and the latter a free man, concerning whose disposition and manner of life it will be well to make a few observations.