BG 13.21

13.21 कार्यकारणकर्तृत्वे in the production of the effect? and the cause? हेतुः the cause? प्रकृतिः Prakriti? उच्यते is said (to be)? पुरुषः Purusha? सुखदुःखानाम् of pleasure and pain? भोक्तृत्वे in the experience? हेतुः the cause? उच्यते is said (to be).Commentary Pleasure and pain are the fruits of virtuous and vicious actions. The force of desire acts on the mind and the mind impels the senses to act to get the objects of desire. Good and evil actions proceed from Nature and lead to happiness or misery. Evil actions produce misery and sorrow. Virtuous actions cause happiness and joy. The soul is the enjoyer. The wife works and prepares nice? palatable dishes the huand silently enjoys the fruits of her labour. He sits ietly and eats them to his hearts content. Even so Nature works and the soul experiences the fruits of Her labour? viz.? pleasure and pain.When harmony predominates? virtuous actions are performed. When there is a preponderance of Rajas? both virtuous and vicious actions are performed. When Tamas predominates? sinful? unlawful and unrighteous actions are done.In the place of Kaarana (कारण) which means cause? some read Karana (करण) which means instrument such as the five organs of knowledge? five organs of action? mind? intellect and egoism (thirteen principles located in the body).Karya The effect? viz.? the physical body. The five elements which form the body and the five senses? and which form the senseobjects which are born of Nature come under the term effect. All alities? such as pleasure and pain and delusion which are born of Nature? come under the term instruments because these alities reside in the instruments? the senses.In the production of the body? the senses and their sensations Nature is said to be the cause. Thus Nature is the cause of Samsara.Sugarcane is the cause. Sugarcane juice? sugar and sugarcandy are the effects or modifications of sugarcane. Milk is the cause. Curd? butter and ghee (meleted butter) are the modifications of milk. Whatever is a modification of something is its effect? and that from which the modifications come is their cause. Nature is the source or cause of all modifications. She generates everything. The ten organs? mind and the five objects of the senses are the sixteen modifications or effects.Mahat (intellect) is born of Mulaprakriti. From Mahat Ahamkara (egoism) is born. Mahat is the effect of Mulaprakriti and the cause of Ahamkara. Therefore Mahat is called PrakritiVikriti. Mahat? Ahamkara and the five Tanmatras (rootelements of matter) are the seven PrakritiVikriti. Each of these is a modification of its predecessor and is in turn the cause of its successor. The five rootelements generate the five gross elements. They are the subtle elements. These seven are both Nature and modification (Prakriti and Vikriti)? cause and effect? and are included under the term cause.The functions of the body? senses? lifeforce? mind and intellect are superimposed on the pure Self. So the ignorant man says I am black I am fat I am hungry I am angry I am deaf I am blind I am the son of so and so? I know? I am the doer? I am the enjoyer? etc.The intellect is very subtle. It is in close contact with the most subtle Self. The Consciousness of the Self is reflected in the intellect (Chidabhasa) and so the intellect which has the semblance of,the Consciousness feels I am pure consciousness or Chaitanya. I experience pleasure and pain. The attributes of the pure Self are superimposed on the intellect. There is mutual superimposition between the intellect and the Self? Nature and Spirit. This is the cause of Samsara.Purusha? Jiva? Kshetrajna and Bhokta are all synonymous terms. Purusha here referred to is not the Supreme Self. He is the conditioned soul? the soul subject to transmigration who experiences pleasure and pain. The Self or the Absolute is ever free from Samsara and is unchanging.Prakriti and Purusha are the cause of Samsara. Nature generates the body? lifeforce? mind? intellect and the senses. The soul experiences pleasure and pain. Samsara is the experience of pleasure and pain. The soul is the Samsarin. He is the experiencer of pleasure and pain. (Cf.XV.9)

— vedicscriptures · exposition · source ↗

The different manifestations of body and senses among the living entities are due to material nature. There are 8,400,000 different species of life, and these varieties are creations of the material nature. They arise from the different sensual pleasures of the living entity, who thus desires to live in this body or that. When he is put into different bodies, he enjoys different kinds of happiness and distress. His material happiness and distress are due to his body, and not to himself as he is. In his original state there is no doubt of enjoyment; therefore that is his real state. Because of the desire to lord it over material nature, he is in the material world. In the spiritual world there is no such thing. The spiritual world is pure, but in the material world everyone is struggling hard to acquire different kinds of pleasures for the body. It might be more clear to state that this body is the effect of the senses. The senses are instruments for gratifying desire. Now, the sum total – body and instrument senses – is offered by material nature, and as will be clear in the next verse, the living entity is blessed or damned with circumstances according to his past desire and activity. According to one’s desires and activities, material nature places one in various residential quarters. The being himself is the cause of his attaining such residential quarters and his attendant enjoyment or suffering. Once placed in some particular kind of body, he comes under the control of nature because the body, being matter, acts according to the laws of nature. At that time, the living entity has no power to change that law. Suppose an entity is put into the body of a dog. As soon as he is put into the body of a dog, he must act like a dog. He cannot act otherwise. And if the living entity is put into the body of a hog, then he is forced to eat stool and act like a hog. Similarly, if the living entity is put into the body of a demigod, he must act according to his body. This is the law of nature. But in all circumstances, the Supersoul is with the individual soul. That is explained in the Vedas ( Muṇḍaka Upaniṣad 3.1.1) as follows: dvā suparṇā sayujā sakhāyaḥ. The Supreme Lord is so kind upon the living entity that He always accompanies the individual soul and in all circumstances is present as the Supersoul, or Paramātmā.

— vedicscriptures · exposition · source ↗