the essence of a triangle, that the three angles are equal to two
right angles.
3. This doctrine raises social life, inasmuch as it teaches
us to hate no man, neither to despise, to deride, to envy, or to
be angry with any. Further, as it tells us that each should be
content with his own, and helpful to his neighbour, not from any
womanish pity, favour, or superstition, but solely by the
guidance of reason, according as the time and occasion demand, as
I will show in Part III.
4. Lastly, this doctrine confers no small advantage on the
commonwealth; for it teaches how citizens should be governed and
led, not so as to become slaves, but so that they may freely do
whatsoever things are best.
I have thus fulfilled the promise made at the beginning of
this note, and I thus bring the second part of my treatise to a
close. I think I have therein explained the nature and
properties of the human mind at sufficient length, and,
considering the difficulty of the subject, with sufficient
clearness. I have laid a foundation, whereon may be raised many
excellent conclusions of the highest utility and most necessary
to be known, as will, in what follows, be partly made plain.
PART III.
ON THE ORIGIN AND NATURE OF THE EMOTIONS
Most writers on the emotions and on human conduct seem to be
treating rather of matters outside nature than of natural
phenomena following nature's general laws. They appear to
conceive man to be situated in nature as a kingdom within a
kingdom: for they believe that he disturbs rather than follows
nature's order, that he has absolute control over his actions,
and that he is determined solely by himself. They attribute
human infirmities and fickleness, not to the power of nature in
general, but to some mysterious flaw in the nature of man, which
accordingly they bemoan, deride, despise, or, as usually happens,
abuse: he, who succeeds in hitting off the weakness of the human
mind more eloquently or more acutely than his fellows, is looked
upon as a seer. Still there has been no lack of very excellent
men (to whose toil and industry I confess myself much indebted),
who have written many noteworthy things concerning the right way
of life, and have given much sage advice to mankind. But no one,
so far as I know, has defined the nature and strength of the
emotions, and the power of the mind against them for their
restraint.
I do not forget, that the illustrious Descartes, though he
believed, that the mind has absolute power over its actions,
strove to explain human emotions by their primary causes, and, at
the same time, to point out a way, by which the mind might attain
to absolute dominion over them. However, in my opinion, he
accomplishes nothing beyond a display of the acuteness of his own
great intellect, as I will show in the proper place. For the
present I wish to revert to those, who would rather abuse or
deride human emotions than understand them. Such persons will,
doubtless think it strange that I should attempt to treat of
human vice and folly geometrically, and should wish to set forth
with rigid reasoning those matters which they cry out against as
repugnant to reason, frivolous, absurd, and dreadful. However,
such is my plan. Nothing comes to pass in nature, which can be
set down to a flaw therein; for nature is always the same, and
everywhere one and the same in her efficacy and power of action;
that is, nature's laws and ordinances, whereby all things come to
pass and change from one form to another, are everywhere and
always the same; so that there should be one and the same method
of understanding the nature of all things whatsoever, namely,
through nature's universal laws and rules. Thus the passions of
hatred, anger, envy, and so on, considered in themselves, follow
from this same necessity and efficacy of nature; they answer to
certain definite causes, through which they are understood, and
possess certain properties as worthy of being known as the
properties of anything else, whereof the contemplation in itself
affords us delight. I shall, therefore, treat of the nature and
strength of the emotions according to the same method, as I
employed heretofore in my investigations concerning God and the
mind. I shall consider human actions and desires in exactly the
same manner, as though I were concerned with lines, planes, and
solids.
DEFINITIONS
I. By an adequate cause, I mean a cause through which its effect
can be clearly and distinctly perceived. By an inadequate or
partial cause, I mean a cause through which, by itself, its
effect cannot be understood.
II. I say that we act when anything takes place, either within
us or externally to us, whereof we are the adequate cause; that
is (by the foregoing definition) when through our nature
something takes place within us or externally to us, which can
through our nature alone be clearly and distinctly understood.
On the other hand, I say that we are passive as regards something
when that something takes place within us, or follows from our
nature externally, we being only the partial cause.
III. By emotion I mean the modifications of the body, whereby
the active power of the said body is increased or diminished,
aided or constrained, and also the ideas of such modifications.
N.B. If we can be the adequate cause of any of these
modifications, I then call the emotion an activity, otherwise I
call it a passion, or state wherein the mind is passive.
POSTULATES
I. The human body can be affected in many ways, whereby its
power of activity is increased or diminished, and also in other
ways which do not render its power of activity either greater or
less.
N.B. This postulate or axiom rests on Postulate i. and
Lemmas v. and vii., which see after II. xiii.
II. The human body can undergo many changes, and, nevertheless,
retain the impressions or traces of objects (cf. II. Post. v.),
and, consequently, the same images of things (see note II.
xvii.).
PROP. I. Our mind is in certain cases active, and in certain
cases passive. In so far as it has adequate ideas it is
necessarily active, and in so far as it has inadequate ideas, it
is necessarily passive.
Proof.--In every human mind there are some adequate ideas, and
some ideas that are fragmentary and confused (II. xl. note).
Those ideas which are adequate in the mind are adequate also in
God, inasmuch as he constitutes the essence of the mind (II. xl.
Coroll.), and those which are inadequate in the mind are likewise
(by the same Coroll.) adequate in God, not inasmuch as he
contains in himself the essence of the given mind alone, but as
he, at the same time, contains the minds of other things. Again,
from any given idea some effect must necessarily follow (I. 36);
of this effect God is the adequate cause (III. Def. i.), not
inasmuch as he is infinite, but inasmuch as he is conceived as
affected by the given idea (II. ix.). But of that effect whereof
God is the cause, inasmuch as he is affected by an idea which is
adequate in a given mind, of that effect, I repeat, the mind in
question is the adequate cause (II. xi. Coroll.). Therefore our
mind, in so far as it has adequate ideas (III. Def. ii.), is in
certain cases necessarily active; this was our first point.
Again, whatsoever necessarily follows from the idea which is
adequate in God, not by virtue of his possessing in himself the
mind of one man only, but by virtue of his containing, together
with the mind of that one man, the minds of other things also, of
such an effect (II. xi. Coroll.) the mind of the given man is not
an adequate, but only a partial cause; thus (III. Def. ii.) the
mind, inasmuch as it has inadequate ideas, is in certain cases
necessarily passive; this was our second point. Therefore our
mind, &c. Q.E.D.
Corollary.--Hence it follows that the mind is more or less
liable to be acted upon, in proportion as it possesses inadequate
ideas, and, contrariwise, is more or less active in proportion as
it possesses adequate ideas.
PROP. II. Body cannot determine mind to think, neither can mind
determine body to motion or rest or any state different from
these, if such there be.
Proof.--All modes of thinking have for their cause God, by
virtue of his being a thinking thing, and not by virtue of his
being displayed under any other attribute (II. vi.). That,
therefore, which determines the mind to thought is a mode of
thought, and not a mode of extension; that is (II. Def. i.), it
is not body. This was our first point. Again, the motion and
rest of a body must arise from another body, which has also been
determined to a state of motion or rest by a third body, and
absolutely everything which takes place in a body must spring
from God, in so far as he is regarded as affected by some mode of
extension, and not by some mode of thought (II. vi.); that is,
it cannot spring from the mind, which is a mode of thought. This
was our second point. Therefore body cannot determine mind, &c.
Q.E.D.
Note.--This is made more clear by what was said in the note to
II. vii., namely, that mind and body are one and the same thing,
conceived first under the attribute of thought, secondly, under
the attribute of extension. Thus it follows that the order or
concatenation of things is identical, whether nature be conceived
under the one attribute or the other; consequently the order of
states of activity and passivity in our body is simultaneous in
nature with the order of states of activity and passivity in the
mind. The same conclusion is evident from the manner in which we
proved II. xii.
Nevertheless, though such is the case, and though there be no
further room for doubt, I can scarcely believe, until the fact is
proved by experience, that men can be induced to consider the
question calmly and fairly, so firmly are they convinced that it
is merely at the bidding of the mind, that the body is set in
motion or at rest, or performs a variety of actions depending
solely on the mind's will or the exercise of thought. However,
no one has hitherto laid down the limits to the powers of the
body, that is, no one has as yet been taught by experience what
the body can accomplish solely by the laws of nature, in so far
as she is regarded as extension. No one hitherto has gained such
an accurate knowledge of the bodily mechanism, that he can
explain all its functions; nor need I call attention to the fact
that many actions are observed in the lower animals, which far
transcend human sagacity, and that somnambulists do many things
in their sleep, which they would not venture to do when awake:
these instances are enough to show, that the body can by the sole
laws of its nature do many things which the mind wonders at.
Again, no one knows how or by what means the mind moves the
body, nor how many various degrees of motion it can impart to the
body, nor how quickly it can move it. Thus, when men say that
this or that physical action has its origin in the mind, which
latter has dominion over the body, they are using words without
meaning, or are confessing in specious phraseology that they are
ignorant of the cause of the said action, and do not wonder at
it.
But, they will say, whether we know or do not know the means
whereby the mind acts on the body, we have, at any rate,
experience of the fact that unless the human mind is in a fit
state to think, the body remains inert. Moreover, we have
experience, that the mind alone can determine whether we speak or
are silent, and a variety of similar states which, accordingly,
we say depend on the mind's decree. But, as to the first point,
I ask such objectors, whether experience does not also teach,
that if the body be inactive the mind is simultaneously unfitted
for thinking? For when the body is at rest in sleep, the mind
simultaneously is in a state of torpor also, and has no power of
thinking, such as it possesses when the body is awake. Again, I
think everyone's experience will confirm the statement, that the
mind is not at all times equally fit for thinking on a given
subject, but according as the body is more or less fitted for
being stimulated by the image of this or that object, so also is
the mind more or less fitted for contemplating the said object.
But, it will be urged, it is impossible that solely from the
laws of nature considered as extended substance, we should be
able to deduce the causes of buildings, pictures, and things of
that kind, which are produced only by human art; nor would the
human body, unless it were determined and led by the mind, be
capable of building a single temple. However, I have just
pointed out that the objectors cannot fix the limits of the
body's power, or say what can be concluded from a consideration
of its sole nature, whereas they have experience of many things
being accomplished solely by the laws of nature, which they would
never have believed possible except under the direction of mind:
such are the actions performed by somnambulists while asleep, and
wondered at by their performers when awake. I would further call
attention to the mechanism of the human body, which far surpasses
in complexity all that has been put together by human art, not to
repeat what I have already shown, namely, that from nature, under
whatever attribute she be considered, infinite results follow.
As for the second objection, I submit that the world would be
much happier, if men were as fully able to keep silence as they
are to speak. Experience abundantly shows that men can govern
anything more easily than their tongues, and restrain anything
more easily than their appetites; when it comes about that many
believe, that we are only free in respect to objects which we
moderately desire, because our desire for such can easily be
controlled by the thought of something else frequently
remembered, but that we are by no means free in respect to what
we seek with violent emotion, for our desire cannot then be
allayed with the remembrance of anything else. However, unless
such persons had proved by experience that we do many things
which we afterwards repent of, and again that we often, when
assailed by contrary emotions, see the better and follow the
worse, there would be nothing to prevent their believing that we
are free in all things. Thus an infant believes that of its own
free will it desires milk, an angry child believes that it freely
desires vengeance, a timid child believes that it freely desires
to run away; further, a drunken man believes that he utters from
the free decision of his mind words which, when he is sober, he
would willingly have withheld: thus, too, a delirious man, a
garrulous woman, a child, and others of like complexion, believe
that they speak from the free decision of their mind, when they
are in reality unable to restrain their impulse to talk.
Experience teaches us no less clearly than reason, that men
believe themselves to be free, simply because they are conscious
of their actions, and unconscious of the causes whereby those
actions are determined; and, further, it is plain that the
dictates of the mind are but another name for the appetites, and
therefore vary according to the varying state of the body.
Everyone shapes his actions according to his emotion, those who
are assailed by conflicting emotions know not what they wish;
those who are not attacked by any emotion are readily swayed this
way or that. All these considerations clearly show that a mental
decision and a bodily appetite, or determined state, are
simultaneous, or rather are one and the same thing, which we call
decision, when it is regarded under and explained through the
attribute of thought, and a conditioned state, when it is
regarded under the attribute of extension, and deduced from the
laws of motion and rest. This will appear yet more plainly in
the sequel. For the present I wish to call attention to another
point, namely, that we cannot act by the decision of the mind,
unless we have a remembrance of having done so. For instance, we
cannot say a word without remembering that we have done so.
Again, it is not within the free power of the mind to remember or
forget a thing at will. Therefore the freedom of the mind must
in any case be limited to the power of uttering or not uttering
something which it remembers. But when we dream that we speak,
we believe that we speak from a free decision of the mind, yet we
do not speak, or, if we do, it is by a spontaneous motion of the
body. Again, we dream that we are concealing something, and we
seem to act from the same decision of the mind as that, whereby
we keep silence when awake concerning something we know. Lastly,
we dream that from the free decision of our mind we do something,
which we should not dare to do when awake.
Now I should like to know whether there be in the mind two
sorts of decisions, one sort illusive, and the other sort free?
If our folly does not carry us so far as this, we must
necessarily admit, that the decision of the mind, which is
believed to be free, is not distinguishable from the imagination
or memory, and is nothing more than the affirmation, which an
idea, by virtue of being an idea, necessarily involves (II.
xlix.). Wherefore these decisions of the mind arise in the mind
by the same necessity, as the ideas of things actually existing.
Therefore those who believe, that they speak or keep silence or
act in any way from the free decision of their mind, do but dream
with their eyes open.
PROP. III. The activities of the mind arise solely from adequate
ideas; the passive states of the mind depend solely on
inadequate ideas.
Proof.--The first element, which constitutes the essence of
the mind, is nothing else but the idea of the actually existent
body (II. xi. and xiii.), which (II. xv.) is compounded of many
other ideas, whereof some are adequate and some inadequate (II.
xxix. Coroll., II. xxxviii. Coroll.). Whatsoever therefore
follows from the nature of mind, and has mind for its proximate
cause, through which it must be understood, must necessarily
follow either from an adequate or from an inadequate idea. But
in so far as the mind (III. i.) has inadequate ideas, it is
necessarily passive: wherefore the activities of the mind follow
solely from adequate ideas, and accordingly the mind is only
passive in so far as it has inadequate ideas. Q.E.D.
Note.--Thus we see, that passive states are not attributed to
the mind, except in so far as it contains something involving
negation, or in so far as it is regarded as a part of nature,
which cannot be clearly and distinctly perceived through itself
without other parts: I could thus show, that passive states are
attributed to individual things in the same way that they are
attributed to the mind, and that they cannot otherwise be
perceived, but my purpose is solely to treat of the human mind.
PROP. IV. Nothing can be destroyed, except by a cause external
to itself.
Proof.--This proposition is self--evident, for the definition
of anything affirms the essence of that thing, but does not
negative it; in other words, it postulates the essence of the
thing, but does not take it away. So long therefore as we regard
only the thing itself, without taking into account external
causes, we shall not be able to find in it anything which could
destroy it. Q.E.D.
PROP. V. Things are naturally contrary, that is, cannot exist in
the same object, in so far as one is capable of destroying the
other.
Proof.--If they could agree together or co--exist in the same
object, there would then be in the said object something which
could destroy it; but this, by the foregoing proposition, is
absurd, therefore things, &c. Q.E.D.
PROP. VI. Everything, in so far as it is in itself, endeavours
to persist in its own being.
Proof.--Individual things are modes whereby the attributes of
God are expressed in a given determinate manner (I. xxv. Coroll.);
that is, (I. xxxiv.), they are things which express in a given
determinate manner the power of God, whereby God is and acts;
now no thing contains in itself anything whereby it can be
destroyed, or which can take away its existence (III. iv.); but
contrariwise it is opposed to all that could take away its
existence (III. v.). Therefore, in so far as it can, and in so
far as it is in itself, it endeavours to persist in its own
being. Q.E.D.
PROP. VII. The endeavour, wherewith everything endeavours to
persist in its own being, is nothing else but the actual essence
of the thing in question.
Proof.--From the given essence of any thing certain
consequences necessarily follow (I. xxxvi.), nor have things any
power save such as necessarily follows from their nature as
determined (I. xxix.); wherefore the power of any given thing,
or the endeavour whereby, either alone or with other things, it
acts, or endeavours to act, that is (III. vi.), the power or
endeavour, wherewith it endeavours to persist in its own being,
is nothing else but the given or actual essence of the thing in
question. Q.E.D.
PROP. VIII. The endeavour, whereby a thing endeavours to persist
in its own being, involves no finite time, but an indefinite
time.
Proof.--If it involved a limited time, which should determine
the duration of the thing, it would then follow solely from that
power whereby the thing exists, that the thing could not exist
beyond the limits of that time, but that it must be destroyed;
but this (III. iv.) is absurd. Wherefore the endeavour wherewith
a thing exists involves no definite time; but, contrariwise,
since (III. iv.) it will by the same power whereby it already
exists always continue to exist, unless it be destroyed by some
external cause, this endeavour involves an indefinite time.
PROP. IX. The mind, both in so far as it has clear and distinct
ideas, and also in so far as it has confused ideas, endeavours to
persist in its being for an indefinite period, and of this
endeavour it is conscious.
Proof.--The essence of the mind is constituted by adequate and
inadequate ideas (III. iii.), therefore (III. vii.), both in so
far as it possesses the former, and in so far as it possesses the
latter, it endeavours to persist in its own being, and that for
an indefinite time (III. viii.). Now as the mind (II. xxiii.) is
necessarily conscious of itself through the ideas of the
modifications of the body, the mind is therefore (III. vii.)
conscious of its own endeavour.
Note.--This endeavour, when referred solely to the mind, is
called will, when referred to the mind and body in conjunction it
is called appetite; it is, in fact, nothing else but man's
essence, from the nature of which necessarily follow all those
results which tend to its preservation; and which man has thus
been determined to perform.
Further, between appetite and desire there is no difference,
except that the term desire is generally applied to men, in so
far as they are conscious of their appetite, and may accordingly
be thus defined: Desire is appetite with consciousness thereof.
It is thus plain from what has been said, that in no case do we
strive for, wish for, long for, or desire anything, because we
deem it to be good, but on the other hand we deem a thing to be
good, because we strive for it, wish for it, long for it, or
desire it.
PROP. X. An idea, which excludes the existence of our body,
cannot be postulated in our mind, but is contrary thereto.
Proof.--Whatsoever can destroy our body, cannot be postulated
therein (III. v.). Therefore neither can the idea of such a
thing occur in God, in so far as he has the idea of our body (II.
ix. Coroll.); that is (II. xi., xiii.), the idea of that thing
cannot be postulated as in our mind, but contrariwise, since (II.
xi., xiii.) the first element, that constitutes the essence of
the mind, is the idea of the human body as actually existing, it
follows that the first and chief endeavour of our mind is the
endeavour to affirm the existence of our body: thus, an idea,
which negatives the existence of our body, is contrary to our
mind, &c. Q.E.D.
PROP. XI. Whatsoever increases or diminishes, helps or hinders
the power of activity in our body, the idea thereof increases or
diminishes, helps or hinders the power of thought in our mind.
Proof.--This proposition is evident from II. vii. or from II.
xiv.
Note.--Thus we see, that the mind can undergo many changes,
and can pass sometimes to a state of greater perfection,
sometimes to a state of lesser perfection. These passive states
of transition explain to us the emotions of pleasure and pain.
By pleasure therefore in the following propositions I shall
signify a passive state wherein the mind passes to a greater
perfection. By pain I shall signify a passive state wherein the
mind passes to a lesser perfection. Further, the emotion of
pleasure in reference to the body and mind together I shall call
stimulation (titillatio) or merriment (hilaritas), the emotion of
pain in the same relation I shall call suffering or melancholy.
But we must bear in mind, that stimulation and suffering are
attributed to man, when one part of his nature is more affected
than the rest, merriment and melancholy, when all parts are alike
affected. What I mean by desire I have explained in the note to
Prop. ix. of this part; beyond these three I recognize no other
primary emotion; I will show as I proceed, that all other
emotions arise from these three. But, before I go further, I
should like here to explain at greater length Prop. x of this
part, in order that we may clearly understand how one idea is
contrary to another. In the note to II. xvii. we showed that the
idea, which constitutes the essence of mind, involves the
existence of body, so long as the body itself exists. Again, it
follows from what we pointed out in the Corollary to II. viii.,
that the present existence of our mind depends solely on the
fact, that the mind involves the actual existence of the body.
Lastly, we showed (II. xvii., xviii. and note) that the power of
the mind, whereby it imagines and remembers things, also depends
on the fact, that it involves the actual existence of the body.
Whence it follows, that the present existence of the mind and its
power of imagining are removed, as soon as the mind ceases to
affirm the present existence of the body. Now the cause, why the
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500