A man of knowledge is one who has followed truthfully the hardships of learning, a man who has, without rushing or without faltering, gone as far as he can in unraveling the secrets of power and knowledge. To become a man of knowledge one must challenge and defeat his four natural enemies.
When a man starts to learn, he is never clear about his objectives. His purpose is faulty; his intent is vague. He hopes for rewards that will never materialize for he knows nothing of the hardships of learning.
He slowly begins to learn–bit by bit at first, then in big chunks. And his thoughts soon clash. What he learns is never what he pictured, or imagined, and so he begins to be afraid. Learning is never what one expects. Every step of learning is a new task, and the fear the man is experiencing begins to mount mercilessly, unyieldingly. His purpose becomes a battlefield.
And thus he has stumbled upon the first of his natural enemies: fear! A terrible enemy–treacherous, and difficult to overcome. It remains concealed at every turn of the way, prowling, waiting. And if the man, terrified in its presence, runs away, his enemy will have put an end to his quest and he will never learn. He will never become a man of knowledge. He will perhaps be a bully, or a harmless, scared man; at any rate, he will be a defeated man. His first enemy will have put an end to his cravings.
It is not possible for a man to abandon himself to fear for years, then finally conquer it. 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.
Therefore he must not run away. He must defy his fear, and in spite of it he must take the next step in learning, and the next, and the next. He must be fully afraid, and yet he must not stop. That is the rule! And a moment will come when his first enemy retreats. The man begins to feel sure of himself. His intent becomes stronger. Learning is no longer a terrifying task.
When this joyful moment comes, the man can say without hesitation that he has defeated his first natural enemy. It happens little by little, and yet the fear is vanquished suddenly and fast. Once a man has vanquished fear, he is free from it for the rest of his life because, instead of fear, he has acquired clarity–a clarity of mind which erases fear. By then a man knows his desires; he knows how to satisfy those desires. He can anticipate the new steps of learning and a sharp clarity surrounds everything. The man feels that nothing is concealed.
And thus he has encountered his second enemy: Clarity! That clarity of mind, which is so hard to obtain, dispels fear, but also blinds. It forces the man never to doubt himself. It gives him the assurance he can do anything he pleases, for he sees clearly into everything. And he is courageous because he is clear, and he stops at nothing because he is clear. But all that is a mistake; it is like something incomplete. If the man yields to this make-believe power, he has succumbed to his second enemy and will be patient when he should rush. And he will fumble with learning until he winds up incapable of learning anything more. His second enemy has just stopped him cold from trying to become a man of knowledge. Instead, the man may turn into a buoyant warrior, or a clown. Yet the clarity for which he has paid so dearly will never change to darkness and fear again. He will be clear as long as he lives, but he will no longer learn, or yearn for, anything.
He must do what he did with fear: he must defy his clarity and use it only to see, and wait patiently and measure carefully before taking new steps; he must think, above all, that his clarity is almost a mistake. And a moment will come when he will understand that his clarity was only a point before his eyes. And thus he will have overcome his second enemy, and will arrive at a position where nothing can harm him anymore. This will not be a mistake. It will not be only a point before his eyes. It will be true power.
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, but he will never lose his clarity or his power.
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.
Once one of these enemies overpowers a man there is nothing he can do. It is not possible, for instance, that a man who is defeated by power may see his error and mend his ways. Once a man gives in he is through. If, however, he is temporarily blinded by power, and then refuses it, 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.
He has to come to realize that 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.
The man will be, by then, at the end of his journey of learning, and almost without warning he will come upon the last of his enemies: Old age! This enemy is the cruelest of all, the one he won’t be able to defeat completely, but only fight away.
This is the time when a man has no more fears, no more impatient clarity of mind–a time when all his power is in check, but also the time when he has an unyielding desire to rest. If he gives in totally to his desire to lie down and forget, if he soothes himself in tiredness, he will have lost his last round, and his enemy will cut him down into a feeble old creature. His desire to retreat will overrule all his clarity, his power, and his knowledge.
But if the man sloughs off his tiredness, and lives his fate through, he can then be called a man of knowledge, if only for the brief moment when he succeeds in fighting off his last, invincible enemy. That moment of clarity, power, and knowledge is enough.
==Carlos Castaneda, “The Teachings of Don Juan”