Such being an account of just and unjust actions, it is their voluntary performance that
constitutes just and unjust conduct. If a man does them involuntarily, he cannot be said
to act justly, or unjustly, except incidentally, in the sense that he does an act which
happens to be just or unjust.
Whether therefore an action
is or is not an act of injustice, or of justice,
depends on its voluntary or involuntary character. When it is involuntary, the agent is
blamed, and only in that case is the action an act of injustice; so that it is possible
for an act to be unjust without being an act of injustice, if the qualification of
voluntariness be absent.
By a voluntary action, as has
been said before,1
I mean any action
within the agent's own control which he performs knowingly, that is, without being in
ignorance of the person affected, the instrument employed, and the result （for
example, he must know whom he strikes, and with what weapon, and the effect of the
blow）; and in each of these respects both accident2
and compulsion must be excluded. For
instance, if A took hold of B's hand and with it struck C, B would not be a voluntary
agent, since the act would not be in his own control. Or again, a man may strike his
father without knowing that it is his father, though aware that he is striking some
person, and perhaps that it is one or other of the persons present3
; and ignorance may be
similarly defined with reference to the result, and to the circumstances of the action
generally. An involuntary act is therefore an act done in ignorance, or else one that
though not done in ignorance is not in the agent's control, or is done under compulsion;
since there are many natural processes too that we perform or undergo knowingly, though none
of them is either voluntary or involuntary4
; for example, growing old, and
Also an act may be either just or unjust incidentally. A man may restore a deposit
unwillingly and from fear of consequences, and we must not then say that he does a just
act, nor that he acts justly, except incidentally; and similarly a man who under
compulsion and against his will fails to restore a deposit can only be said to act
unjustly or do what is unjust incidentally.
Again voluntary acts are divided into acts done by choice and those done not by choice,
the former being those done after deliberation and the latter those done without previous
There are then three ways5
in which a man may injure his fellow. An injury done in ignorance is an error, the person
affected or the act or the instrument or the result being other than the agent supposed;
for example, he did not think to hit, or not with this missile, or not this person, or not
with this result, but it happened that either the result was other than he expected
（for instance he did not mean to inflict a wound but only a prick）, or
the person, or the missile.
When then the injury happens
contrary to reasonable expectation, it is （1） a misadventure. When,
though not contrary to reasonable expectation, it is done without evil intent, it is
（2） a culpable error; for an error is culpable when the cause of one's
ignorance lies in oneself, but only a misadventure when the cause lies outside oneself.
When an injury is done knowingly but not deliberately, it
is （3） an act of injustice or wrong; such, for instance, are injuries
done through anger, or any other unavoidable or natural passion to which men are liable;
since in committing these injuries and errors a man acts unjustly, and his action is an
act of injustice, but he is not ipso facto
unjust or wicked,
for the injury was not done out of wickedness. When however an injury is done from choice,
the doer is unjust and wicked.
Hence acts due to sudden
anger are rightly held not to be done of malice aforethought, for it is the man who gave
the provocation that began it, not he who does the deed in a fit of passion.
And moreover the issue is not one of fact, but of justification
（since it is apparent injustice that arouses anger）; the fact of the
injury is not disputed （as it is in cases of contract, where one or the other of
the parties must be a knave, unless they dispute the facts out of forgetfulness）.
They agree as to the facts but dispute on which side justice lies so that one thinks he
has been unjustly treated and the other does not. On the other hand, one who has planned
an injury is not acting in ignorance;6
but if a man does an injury of set purpose, he is guilty of
injustice, and injustice of the sort that renders the doer an unjust man, if it be an act
that violates proportion or equality. Similarly one who acts justly on purpose is a just
man; but he acts justly only if he acts voluntarily.
Of involuntary actions some are pardonable and some are not. Errors not merely committed
in ignorance but caused by ignorance are pardonable; those committed in ignorance, but
caused not by that ignorance but by unnatural or inhuman passion, are