Prabhupāda: By speculation, the real world for them is negation of this world. That is voidism. I am experiencing everything here material, so this material thinking and other material thinking induces him to conclude that it must be opposite. It must be opposite. This is material. So spiritual means not this form, or formless, or void. So that is also material thinking. Just the opposite number.
Śyāmasundara: He is still proceeding in his method. He comes to some good conclusions. He is trying to understand what makes men's minds work. He says that "Thus this real world becomes an ideal construction in the mind of man."
Prabhupāda: Yes. Ideal construction... Here we are frustrated because everything is temporary; therefore ideal is eternal. That much we can understand. Temporary. Just like I want to live; that is my tendency. Nobody wants to die. But I am hopeless, because this body is not eternal. Therefore ideal life is eternal body.