In plain words
Because the nerves grow weak, all the limbs connected with them grow weak. When it weakens in this way, it does not weaken only for the moment. In a single moment it wastes the strength from six months of the food we have eaten. To gain that strength back takes six months. There is no telling how many times anger will come to us in those six months. Every time anger comes, the span of life grows shorter. The nerves are shaken. Many people know this. When anger comes, the lips tremble. The eyes tremble. The fingers tremble. Everything grows weak. Every limb of the body shakes. We use this anger for the moment and try to get some satisfaction from it, but we cannot see the harm it does to us. This anger harms not the other man but ourselves. In the same way, envy, hatred, Ahaṅkāra and pride in us also work to wear down, little by little, the powers that are in man.
Humanness is the union of body, Manas and Ātma
What is humanness? Humanness is the union of these three: body, Manas and Ātma. Its meaning is this: of them, one is doing, the second is knowing, the third is being. The union of these three is true humanness. Whatever actions are to be done, the body must go first. Even what we eat, we eat with the body! It is the body that does the actions of daily life. So the doer is the body. But only doing is limited to the body; the power to enquire what should be done and what should not be done is in Manas. If one leaves aside the Ātma that is in the mind that knows, and goes on doing actions with the body alone, this is what they called animality. So doing is not what matters most. One must know, and then do. When we do not use the mind that knows, mere doing turns into animality.