Sama-darśinaḥ means equal vision. A learned brāhmaṇa, he is most intelligent man in the human society, so, and a dog . . . superficially, externally, there is much difference. Here is a dog, a street dog, and here is a learned brāhmaṇa. But one who is paṇḍita, one who is Kṛṣṇa conscious, he sees that the paṇḍita and the dog, they are the same, because they are also the same spiritual spark. By his karma, he has become a learned paṇḍita, and by his karma, he has become a dog. But within the different body, dehino 'smin yathā dehe kaumāraṁ (BG 2.13), asmin dehe, in this body there is the soul.
That is his vision. Of course, externally, it is not that I shall behave equally with the brāhmaṇa and the dog. That is external behavior. But internally, we should know that both the brāhmaṇa and the dog, they're a spiritual spark. This is called brahma-jñāna. Brahma-jñāna means the knowledge of spiritual self. That is called brahma-jñāna. So when one attains this brahma-jñāna, then brahma-bhūtaḥ prasannātmā na śocati na kāṅkṣati, samaḥ sarveṣu bhūteṣu (BG 18.54). Samatā, equal. That is brahma-jñāna.
So in this verse Kṛṣṇa says, er, Arjuna says that yad rājya-sukha-lobhena hantuṁ svajanam udyatāḥ (BG 1.44). So when we are killing animals for the satisfaction of our tongue, this is mahat pāpam. Kṛṣṇa, Arjuna says, aho bata mahat pāpam. Mahat pāpam, great sinful act. Great sinful act. If we want to kill anyone, any living entity, for my satisfaction, either my tongue satisfaction or any sense satisfaction, it is mahā-pāpam, great sinful act. Because they are all svajana. You cannot kill, either you take this sense or that sense. But Arjuna is speaking in a limited sense; he is thinking of his own family members. But if one is actually in knowledge, brahma-jñāna, he thinks in the same way that, "The lower animals, they are also our family members. And if I kill him for my satisfaction, my sense satisfaction, it is great sinful act."
Unfortunately, everyone is killing for his sense gratification in the name of religion. In the name of religion, although it is prohibited, still they are killing. Just imagine how much sinful activities they are doing. And how they can be happy? Happiness, of course, a hog also thinks that he is very happy that he is eating stool, living in filthy place, and because he has got the facility of sex life without any discrimination, he may think happy life. But that is not happiness. Happiness is different thing. Sukham ātyantikaṁ yat tad atīndriya-grāhyam (BG 6.21). If you want to feel happiness by your these blunt material senses, that is not happiness. Happiness is beyond your material senses. Ātyantikam. That is real happiness. Real happiness means it will never end, and you will never feel satiation that, "I no more want." That is real happiness. Material happiness, there is no such thing that you will feel immediately satiation. After enjoying any material happiness a few minutes, you will feel, "Again another, again another, again another."
So therefore in the Bhagavad-gītā it is said, sukham ātyantikaṁ yat tat (BG 6.21). So real, what is real happiness, that is not felt by these blunt material senses. So what is that sense? That is purified senses. Sarvopādhi-vinirmuktam tat-paratvena nirmalam (CC Madhya 19.170). When our senses are purified, tat-paratvena, for the sake of Kṛṣṇa, when our senses are employed for the sake of Kṛṣṇa, that is purified senses. Hṛṣīkeṇa hṛṣīkeśa-sevanaṁ bhaktir ucyate. That is wanted.
So here, in the beginning, Arjuna, he's thinking in terms of his blunt senses. But the same thing he will do. Ātyantikam, atīndriya, purified senses. Just try to understand. This is Kṛṣṇa consciousness. Arjuna is now thinking, yad rājya-sukha-lobhena (BG 1.44): "For the matter of getting kingdom and sense gratification, I am going to kill my kinsmen. So it is great sin." That's a fact. If the warfare in the Kurukṣetra battlefield was for Arjuna's sense satisfaction, then it was a great sin. But actually, it is not being done for Arjuna's satisfaction. It is to be done for Kṛṣṇa's satisfaction. So therefore the conclusion should be that whatever we do, if we do it for our own sense satisfaction, that is mahā-pāpam, sinful activities. But if we do the same thing for Kṛṣṇa's satisfaction, that is spiritual advancement. This is the difference.