Sādhya means what for this human form of life we have got. That is called sādhya, the goal, the goal of life. And sādhana. Sādhana means the activity by which we can attain, we can achieve that goal of life. This is called sādhya-sādhana. The Darwin theory, although they are giving some idea of progressive evolution, but he does not know what is the goal of life, why this progress is there. That these rascals they do not know. Simply just imagining, taking some whims from the Padma Purāṇa, Brahmā Vaivarta Purāṇa. Aṣitiṁś catvarāṁś caiva, jīva-jātiṣu, lakṣāṁs tān jīva-jātiṣu. There are 8,400,000 types of jīva-jātis. Aṣitiṁś catvarāṁś caiva lakṣāṁs tān jīva-jātiṣu. So this is already there. Brahmādbhiḥ. In this way the living entity is wandering in the cycle of transmigration of the soul. So from this, Mr. Darwin might have taken some hints, but he could not explain properly. He could not catch up that brahmādbhiḥ, who is wandering. So it is a chaos.
So anyway, why this living entity is wandering, not fixed up? So there must be some goal. He is hankering after that. There must be some goal of life. To achieve that goal of life that is called sādhya. Why we are struggling here for happiness or something else? We are struggling. So this question was raised by Caitanya Mahāprabhu, that "What is the goal of life?" Unless there is goal of life, why there is struggle? Why... There must be some goal of life, sādhya. And sādhana. Sādhana means the means by which we can achieve that goal of life.