BG Chap 13 - The jīva's connection with prakṛti - jīva being the cause
The jīva is the cause of the connection being the enjoyer of happiness and distress which is offered by prakṛti. . The functions of the jīva are to preside over prakṛti and experience happiness and distress. Since prakṛti is the agent in regards to production of the body and senses but is itself exploited by the jīva, the jīva is the principle cause or doer. The living entity is the cause of all his sufferings and enjoyments because he has illicitly embraced māyā with the desire to predominate and enjoy independently of Kṛṣṇa. He thus becomes entangled in material nature. Taking his karma into consideration, material nature then creates for him a field meant ultimately for suffering. This all takes place under the sanction of the actual puruṣa, the Supersoul. Therefore, although nature is the cause of the entire material manifestation, the living entity causes his own happiness and distress. The Lord must also be accepted as the doer or cause in all cases as He will state later in BG 18.14 that the Supersoul is one of the five factors in action.
Even though the body, the senses, the sense devatās and the jīva’s capacity for enjoyment are all qualities of prakṛti, because of the predominance of unconsciousness in the body, senses and sense devatās, and the predominance of consciousness in experiencing happiness and distress, the two get separately designated as causes according to predominance. According to this reasoning, it is said that prakṛti is the cause, by producing the body, sense and sense devatās, and jīva is the cause by his capacity to experience happiness and distress. Even though nature causes the circumstances for a jīva according to his karma, the jīva identifying with the body, causes the suffering or enjoyment.