Macbeth is actuated in his conduct mainly by an
inordinate desire for worldly honors; his delight lies
primarily in buying golden opinions from all sorts of people. But we must not, therefore, deny him an entirely human complexity of motives. For example, his fighting in Duncan's service is magnificent and courageous, and his evident joy in it is traceable in art to the natural pleasure which accompanies the explosive expenditure of prodigious physical energy and the euphoria which follows. He also rejoices no doubt in the success which crowns his efforts in battle - and so on. He may even conceived of the proper motive which should energize back of his great deed:

The service and the loyalty I owe, In doing it, pays itself.
But while he destroys the king's enemies, such motives work but dimly at best and are obscured in his consciousness by more vigorous urges. In the main, as we have said, his nature violently demands rewards: he fights valiantly in order that he may be reported in such terms a "valour's minion" and "Bellona's bridegroom"' he values success because it brings spectacular fame and new titles and royal favor heaped upon him in public. Now so long as these mutable goods are at all commensurate with his inordinate desires - and such is the case, up until he covets the kingship - Macbeth remains an honorable gentleman. He is not a criminal; he has no criminal tendencies. But once permit his self-love to demand a satisfaction which cannot be honorably attained, and he is likely to grasp any dishonorable means to that end which may be safely employed. In other words, Macbeth has much of natural good in him unimpaired; environment has conspired with his nature to make him upright in all his dealings with
those about him. But moral goodness in him is undeveloped and indeed still rudimentary, for his voluntary acts are scarcely brought into harmony with ultimate end. As he returns from victorious battle, puffed up with self-love which demands ever-increasing recognition of his greatness, the demonic forces of evil-symbolized by the Weird Sisters-suggest to his inordinate imagination the splendid prospect of attaining now the greatest mutable good he has
ever desired. These demons in the guise of witches cannot
read his inmost thoughts, but from observation of facial
expression and other bodily manifestations they surmise with comparative accuracy what passions drive him and what dark desires await their fostering. Realizing that he wishes the kingdom, they prophesy that he shall be king. They cannot thus compel his will to evil; but they do arouse his passions and stir up a vehement and inordinate apprehension of the imagination, which so perverts the judgment of reason that it
leads his will toward choosing means to the desired temporal good. Indeed his imagination and passions are so vivid under this evil impulse from without that "nothing is but what is not"; and his reason is so impeded that he judges, "These solicitings cannot be evil, cannot be good." Still, he is provided with so much natural good that he is able to control the apprehensions of his inordinate imagination and decides
to take no step involving crime. His autonomous decision not
to commit murder, however, is not in any sense based upon
moral grounds. No doubt he normally shrinks from the
unnaturalness of regicide; but he so far ignores ultimate
ends that, if he could perform the deed and escape its
consequences here upon this bank and shoal of time, he'ld
jump the life to come. Without denying him still a complexity
of motives - as kinsman and subject he may possibly
experience some slight shade of unmixed loyalty to the King
under his roof-we may even say that the consequences which he
fears are not at all inward and spiritual, It is to be
doubted whether he has ever so far considered the possible
effects of crime and evil upon the human soul-his later
discovery of horrible ravages produced by evil in his own
spirit constitutes part of the tragedy. Hi is mainly
concerned, as we might expect, with consequences involving
the loss of mutable goods which he already possesses and
values highly.
After the murder of Duncan, the natural good in him
compels the acknowledgment that, in committing the unnatural act, he has filed his mind and has given his eternal jewel, the soul, into the possession of those demonic forces which are the enemy of mankind. He recognizes that the acts of conscience which torture him are really expressions of that outraged natural law, which inevitably reduced him as
individual to the essentially human. This is the inescapable
bond that keeps him pale, and this is the law of his own
natural from whose exactions of devastating penalties he
seeks release:

Come, seeling night...
And with thy bloody and invisible hand
Cancel and tear to pieces that great bond
Which keeps me pale.

He conceives that quick escape from the accusations of
conscience may possibly be effected by utter extirpation of
the precepts of natural law deposited in his nature. And he
imagines that the execution of more bloody deeds will serve
his purpose. Accordingly, then, in the interest of personal
safety and in order to destroy the essential humanity in
himself, he instigates the murder of Banquo.

But he gains no satisfying peace because hes conscience
still obliges him to recognize the negative quality of evil
and the barren results of wicked action. The individual who
once prized mutable goods in the form of respect and
admiration from those about him, now discovers that even such
evanescent satisfactions are denied him:

And that which should accompany old age,
As honor, love, obedience, troops of friends,
I must not look to have; but, in their stead,
Curses, not loud but deep, mouth-honour, breath,
Which the poor heart would fain deny, and dare not.

But the man is conscious of a profound abstraction of
something far more precious that temporal goods. His being
has shrunk to such little measure that he has lost his former
sensitiveness to good and evil; he has supped so full with
horrors and the disposition of evil is so fixed in him that
nothing can start him. His conscience is numbed so that he
escapes the domination of fears, and such a consummation may
indeed be called a sort of peace. But it is not entirely what
expected or desires. Back of his tragic volitions is the
ineradicable urge toward that supreme contentment which
accompanies and rewards fully actuated being; the peace which
he attains is psychologically a callousness to pain and
spiritually a partial insensibility to the evidences of
diminished being. His peace is the doubtful calm of utter
negativity, where nothing matters.
This spectacle of spiritual deterioration carried to the
point of imminent dissolution arouses in us, however, a
curious feeling of exaltation. For even after the external
and internal forces of evil have done their worst, Macbeth
remains essentially human and his conscience continues to
witness the diminution of his being. That is to say, there is
still left necessarily some natural good in him; sin cannot
completely deprive him of his rational nature, which is the
root of his inescapable inclination to virtue. We do not need
Hecate to tell us that he is but a wayward son, spiteful and
wrathful, who, as other do, loves for his own ends. This is
apparent throughout the drama; he never sins because, like
the Weird Sisters, he loves evil for its own sake; and
whatever he does is inevitably in pursuance of some apparent
good, even though that apparent good is only temporal of
nothing more that escape from a present evil. At the end, in
spite of shattered nerves and extreme distraction of mind,
the individual passes out still adhering admirably to his
code of personal courage, and the man's conscience still
clearly admonishes that he has done evil.
Moreover, he never quite loses completely the liberty of
free choice, which is the supreme bonum naturae of mankind.
 

But since a wholly free act is one in accordance with reason, in proportion as his reason is more and more blinded by inordinate apprehension of the imagination and passions of the sensitive appetite, his volitions become less and less free. And this accounts for our feeling, toward the end of the drama, that his actions are almost entirely determined
and that some fatality is compelling him to his doom. This
compulsion is in no sense from without-though theologians may
at will interpret it so-as if some god, like Zeus in Greek
tragedy, were dealing out punishment for the breaking of
divine law. It is generated rather from within, and it is not
merely a psychological phenomenon. Precepts of the natural
law-imprints of the eternal law- deposited in his nature have been violated, irrational acts have established habits
tending to further irrationality, and one of the penalties
exacted is dire impairment of the liberty of free choice.
Thus the Fate which broods over Macbeth may be identified
with that disposition inherent in created things, in this
case the fundamental motive principle of human action, by
which providence knits all things in their proper order.
Macbeth cannot escape entirely from his proper order; he must inevitably remain essentially human.