Having heard Krishna express how attracted he is to those who are equipoised towards all things, Arjuna desired to gain better understanding of the knowledge that enables such a perception of the world.
Arjuna: Dear Krishna, I want to understand a few pairs of concepts: prakriti and puruṣa; kṣetra and kṣetra-jña; and jñāna and jñeya. Please explain these terms.
Krishna: Kṣetra means “field.” In philosophy the term refers to your body and its world, which is your “field of activity.”
Kṣetra-jña means “field-knower.” In philosophy this refers to the consciousness that acts within your body, the “field.” Kṣetra-jña refers not only to you, the individual consciousness aware of a single field, but also to me, the super-consciousness aware of all fields.
As for jñāna, that term means “knowledge.” In my opinion, “knowledge” consists of understanding the field and the field-knower.
Arjuna: Please explain more about the field and the field-knower, so that I might become wise with knowledge.
Krishna: Listen carefully to what I have to say about the field, how it works and what it does; and the powers of the field-knower. I will summarize the many different teachings of the sages, the scriptures, and the philosophical codes.
Arjuna: Certainly, I will listen very carefully.
Krishna: Your field-of-activity can be summarized as the interactions between various elements.
Arjuna: What elements?
Krishna: First the five tangible elements: solids, liquids, gasses, energies, and space. And then, the sense of ego, which makes one feel important enough to control and exploit these elements.
Arjuna: Are there more elements in the field-of-activity?
Krishna: Yes, many more. There is intellect, the immediate tool of the ego. And there is the unseen background nature, of which the ego is the immediate tool.
Arjuna: What is the tool of the intellect?
Krishna: It has eleven tools, the eleven senses. The most important is the mind. Then there are the five senses of input (eyes, ears, nose, mouth, and skin) and the five senses of output (voice, hands, legs, genital, and anus).
Arjuna: What are the tools of these senses?
Krishna: The five sense-objects: form, sound, scent, taste, and touch.
Arjuna: Is there anything else in the field?
Krishna: No. These 24 items sufficiently summarize the ingredients on the field-of-activity.