In plain words
The mind is like a fly. Having no power to examine what is lasting and what is passing, it roams about in many ways, wherever it pleases. One moment it settles on sacred prasāda. The very next moment it settles on a dung cart. In the same way, man develops good thoughts in one minute. The next moment people throw the mind into turmoil with bad feelings and evil thoughts that run against them. The mind has no bounds or limits. It has not even the power to enquire, “Is this pure or impure?” Though man has the Buddhi, the power to examine what is lasting and what is passing, he fails to gain the good chance to put this Buddhi to good use. The mind is like an elephant in rut. When the mahout has scrubbed it clean in many ways, washed it with water and brought it to the bank, it throws earth over its head with its trunk. That is its nature. So too is man's state. Though from time to time he cleanses himself in his sādhanas with holy acts and divine feelings, he sprinkles the very sensual desires of the world over his own head and falls into unrest of many kinds. The mind is like a great river in flood. If the flood is to be brought into a tank, the holes the tank has must be closed before that. Without doing so, when one tries to fill the tank with this river water, all this water keeps running out through the breaches the tank has. There is no use in filling it with this water. Man's mind itself is a great lake. The power of the Ātma is a mighty flood. It enters the lake of the mind through the channel called the Buddhi. The tank has been breached by the senses. Only when the senses are mastered can the water called the power of the Ātma stay in this lake of the mind. The mind is the master of the senses. But it keeps submitting to the senses. As a king might submit to his servants, the mind keeps submitting to the senses. What freedom can a great king who has submitted to his servants have? What honour and respect can he bestow? In just the same way, when the mind, which is the master, bows to its own slaves, the senses, man turns into a slave. So man must always remain the master, and never become a servant. The reason is that the mind is losing its power, always, to the wishes of the senses, to the stir of the senses and to the ways of the senses. By the tongue speaking too much in many ways, by seeing sights of many kinds, and by brooding, the power of the mind keeps wasting away.