Bhagavad Gita · Chapter 13: The Field and the Knower of the Field
Bhagavad Gita 13.20
कार्यकारणकर्तृत्वे हेतुः प्रकृतिरुच्यते ।
पुरुषः सुखदुःखानां भोक्तृत्वे हेतुरुच्यते ॥
kāryakāraṇakartṛtve hetuḥ prakṛtirucyate | puruṣaḥ sukhaduḥkhānāṃ bhoktṛtve heturucyate ||
Nature is said to be the cause behind the body, its instruments, and their activity. Spirit is said to be the cause behind the experience of pleasure and pain.
Modern context
A division of labour: nature does all the acting, through the body and its instruments. Spirit is what experiences pleasure and pain. The body runs, the mind thinks, the hands work, all as nature. Yet someone is there to feel it all. This is why the same event can be suffering for one person and peace for another: what differs is not only what happens but how it is experienced.