Just like two lawyers are arguing in the court. The medium is the law court. So neither of them can deny the law court, but one has to establish his convictions by argument, by logic. So similarly, tat tvam asi is the code of Vedic principle or Vedas, "You are that." Tat tvam asi. Tat means that supreme spirit. "You are." So our philosophy, Vaiṣṇava philosophy, we begin from this point. As Kṛṣṇa began Bhagavad-gītā from the point that "You are not this body," we begin from this version, tat tvam asi. Tat tvam asi. "You are not this." That means "What I am?" Then I must be something; otherwise what is my identity? That reply is your identity is that "You are as good as God." That means you are qualitatively the same. Tat tvam asi. Qualitatively you are...
The mistake of the Māyāvāda philosophy is that "You are the same." You are the same in which way? I am the same in quality, not in quantity. Just like if I say, "You are as good as President Nixon," there is nothing wrong because you are American, he is American. Is there anything wrong? From the point of view, American citizenship, you are as good as President Nixon. But when you go deep into the matter, you will find, oh, you are far, far away from President Nixon. Similarly, we are identifying ourself with this matter, but Vedas says that "You are not matter. You are supreme spirit soul." Not supreme, "You are spirit soul."
That understanding is tat tvam asi. You have to understand ahaṁ brahmāsmi: "I am Brahman. I am not matter." Our disease is that I am identifying with this matter, "I am this material body," which is foreign to me. This is the beginning of Bhagavad-gītā instruction, that "You are not this body."Tat tvam asi: "You are spirit soul." So we also have to accept. We are accepting that "I am not this body; I am spirit soul." But my constitutional position is part and parcel of the supreme whole. So just like the gold mine and a small particle of gold. That small particle of gold is also gold. But that does not mean it has the same value as the gold mine. Tat tvam asi. Just like a drop of sea water. Chemical composition is the same. Salty taste is the same.