In plain words
Whatever physical learning man may acquire, if purity of citta, that one thing, is lacking, he cannot understand the Ātma-tattva. However many degrees man may earn, whatever titles he may win, without purity of citta he cannot recognise himself.
Though he has learnt the Vedas and Vedāṅgas by rote, though he is able to put together prose and verse, if purity of citta is lacking, he comes to ruin.
So whether it is learning the lore of the Vedas and Vedāṅgas, or reciting the Śāstras by rote, or being able to compose verse and prose, one without purity of citta is merely a gramophone. One who has eyes can see at least some of the objects in the world when he opens them. However great a scholar he may be, if he has no eyes he cannot see even an object close beside him. One who is in deep sleep, however eminent he may be, cannot see any object, nor the world of the waking state. An innocent who knows no learning at all can see the world once he is awake. In the same way, man is doing ever so many sādhanas. In the spiritual field he carries out ever so many researches. People perform japa, tapas and yāgas. However much one does, purity of citta within is essential. Without it, one cannot take a single step forward in the spiritual life.
He himself is the Ātma-tattva. What is the reason he cannot recognise himself? The lack of purity of citta. Like fire covered with ash, the Ātma is filled over with the ash called distortion. When the ash covering it from above is removed, the fire shows of itself. In the same way, because Ahaṅkāra and mamakāra, the two of them, cover it, he cannot recognise the Ātma-tattva, the divinity within humanness. Only when he roots out this Ahaṅkāra and pride does he recognise this Ātma as himself. For man, Ahaṅkāra is a great danger. Whatever else is lacking, one can still live after a fashion; but through Ahaṅkāra he is in some measure rooting out his own humanness. What is the root cause of this Ahaṅkāra? Is it wealth, or learning, or strength? None of these. All these last but a moment. Yet, leaning on what is impermanent and fleeting, man forgets the divinity that is eternal and true.
Between man and beast there is no difference at all. The beast has a mate and young.