In plain words
On the day we develop such holy feelings in the heart, on that very day the nation. Society, and the world, can reach a high level, a holy level. So we must do sādhana so that, little by little, we press down these thoughts and counter-thoughts to some extent. So we must clearly recognise the Satya that the Manas is no separate form, that it is only the coming together of our thoughts. We have learnt something of the secret of these: the body, the senses and the Manas.
Next we must recognise the secret of the Buddhi. Buddhi simply means the faculty of decision. In Vedānta this itself is called the antaḥkaraṇa. It is also called the antarātma. In a state of being at sixes and sevens over a matter, in a state of confusion. The instrument that decides is the Buddhi. We often say. When some holy feeling arises in us: “My antaḥkaraṇa.” “It is prompting in this way.” Thus. The antaḥkaraṇa is nothing but the decision of the Buddhi. Whether you call it ‘antaḥkaraṇa’ or ‘antarātma’, it is nothing separate. The decision of the Buddhi is the antaḥkaraṇa; the decision of the Buddhi is the inner feeling; the word antarātma has another meaning as well. Since it stands close to the Ātma, the Buddhi has one more name, antarātma. Below is the body; the step above it, the senses; the step higher still, the Manas; the step above that, the Buddhi; and the step above the Buddhi is the Ātma alone! This is what the Bhagavad Gītā has set out, likening the senses to horses, the Manas to the reins and the Buddhi to the charioteer. The horses are always restless and lively. The Manas, the reins, holds very firm. The charioteer stands there as the Buddhi; but who is the master? Who is it that sits in this chariot? He is the Ātma. So, since it is the charioteer of the Ātma, the Buddhi is the decision of the Ātma. That is why the Buddhi is pure. When any owner wants a driver, he makes many efforts to find the right driver. That driver should be one who knows driving well. He should be of good character and one who follows the owner in every way. Only such a man does the owner choose as his driver. When in this world so many qualities are looked for in choosing a driver, how holy must the one be who is the driver of the Ātma? So the one who is … is the Buddhi. So, if the Buddhi has holy qualities, then however virtuous it may be, it may not seat anyone in this chariot without the owner's permission. That is why they said, ‘Buddhigrāhyam atīndriyam’. We must learn the secret that this birth has come to us so that we may know the principle that is beyond even this Buddhi.
Because he is virtuous, he is called buddhimān.