karma-bandham. You act something, and there is reaction. That is called karma-bandha. We can understand very easily: whatever you act, there is reaction. Good act or bad act . . . there are two things. So if while in this body we act piously, then our future is very good. If we act impiously, then our future is not very good. So actually we should act piously, not impiously. That is human life. We should know what kind of action we should do. In the Sixteenth Chapter of Bhagavad-gītā you'll find, pravṛttiṁ ca nivṛttiṁ ca na vidur āsura-janāḥ (BG 16.7): "Those who are asuras, they do not know what kind of action should be done and what kind of action should not be done." Not that "Anything I like, at my whims." That is not . . . at least for human being, he should not do. Even in the state laws, if you act whimsically, whatever you like, you'll be liable to so many difficulties, and what to speak of spiritual life?
So Kṛṣṇa has described so far . . . sāṅkhya yoga means analytical study of the soul and the body. He has very nicely . . . so this analytical study of the soul and body means so far, He has described the activities of the body. That is sāṅkhya yoga. Just like a medical man has got full analysis—not full—to a portion—of this body, the anatomy, the physiology. They have studied how the veins are working, how different secretions are transforming into blood, how the heart is working. This is called analytical study. So eṣā te abhihitā sāṅkhye. So far the body is concerned, that is now fully analyzed.
Now, buddhir yoge tv imām, another department of knowledge, buddhi-yoga. Buddhi-yoga means spiritual life. That is buddhi-yoga. Just like you'll find in the Tenth Chapter, Kṛṣṇa says to Arjuna, buddhi-yogaṁ dadāmi tam. When there is talk between the spirit, supreme spirit, Kṛṣṇa, and the individual spirit, subordinate spirit, the living entity . . . Kṛṣṇa is the Supreme Being, and we are subordinate being. So these people at the present moment, they do not know. But we have to take instruction from Vedas. Nityo nityānāṁ cetanaś cetanānām (Kaṭha Upaniṣad 2.2.13). The Supreme Being, He is eko yo bahūnāṁ vidadhāti kāmān. He is supplying the necessities of life, kāmān, whatever we require. There are so many things for birds, beasts, human being, different types of fruits, flowers, milk. Everything is being supplied by Kṛṣṇa. Therefore He's Supreme Being. How He can be supreme? Just like in a family the father is considered to be supreme. Why? Because he takes care of the whole family, he is supreme. Similarly, the Supreme Person, Kṛṣṇa, He takes care of the whole creation, material and spiritual, innumerable universes, and therefore He's sup . . .
So when we act according to the direction of the Supreme . . . because we are subordinate. This is our position. A subordinate position is that he must act according to the direction of the master or the supreme. That is natural. Everyone is acting like that. So that is called buddhi-yoga. When you act according to the direction of the Supreme, Kṛṣṇa, or His representative, that is called buddhi-yoga. That is real . . . Buddhi means intelligence, and yoga means linking, connecting.