He will know at this point that the power he has been pursuing for so long is finally his. He can do with it whatever he pleases. His ally is at his command. His wish is the rule. He sees all that is around him. But he has also come across his third enemy: POWER!
Power is the strongest of all enemies. And naturally the easiest thing to do is to give in; after all, the man is truly invincible. He commands; he begins by taking calculated risks, and ends in making rules, because he is a master.
A man at this stage hardly notices his third enemy closing in on him. And suddenly, without knowing, he will certainly have lost the battle. His enemy will have turned him into a cruel, capricious man.
Will he lose his power?
No, he will never lose his clarity or his power.
What then will distinguish him from a man of knowledge?
A man who is defeated by power dies without really knowing how to handle it. Power is only a burden upon his fate. Such a man has no command over himself, and cannot tell when or how to use his power.
Is the defeat by any of these enemies a final defeat?
Of course it is final. Once one of these enemies overpowers a man there is nothing he can do.
Is it possible, for instance, that the man who is defeated by power may see his error and mend his ways?
No. Once a man gives in he is through.
But what if he is temporarily blinded by power, and then refuses it?
That means his battle is still on. That means he is still trying to become a man of knowledge. A man is defeated only when he no longer tries, and abandons himself.
But then, don Juan, it is possible that a man may abandon himself to fear for years, but finally conquer it.
No, that is not true. If he gives in to fear he will never conquer it, because he will shy away from learning and never try again. But if he tries to learn for years in the midst of his fear, he will eventually conquer it because he will never have really abandoned himself to it.
How can he defeat his third enemy, don Juan?
He has to defy it, deliberately. He has to come to realize the power he has seemingly conquered is in reality never his. He must keep himself in line at all times, handling carefully and faithfully all that he has learned. If he can see that clarity and power, without his control over himself, are worse than mistakes, he will reach a point where everything is held in check. He will know then when and how to use his power. And thus he will have defeated his third enemy.
(translated to Ukrainian by Oleksandr Korytskyy here).