he first philosophy, he concluded, cogito ergo sum, "I think; therefore I exist." He felt that everything was subject to doubt with the exception of the act of doubting itself. Since doubting is a part of thinking, the act of thinking is an undeniable experience. Therefore he concluded that because I doubt, I think, and because I think, I exist.
Srila Prabhupada: That is a good argument. If I do not exist, how can I think? But is he condemning doubt or accepting doubt? What is his position?
Syamasundara dasa: He accepts doubt as the only real fact. Because I can doubt that my hand exists, it may be a hallucination, a dream. I can doubt that everything perceived exists because it may all be a dream, but the fact that I am doubting cannot be doubted.
Srila Prabhupada: So what is his conclusion? Should one stop doubting or continue doubting? If I doubt everything, I may come to the truth and then doubt the truth.
Syamasundara dasa: His point is that the truth cannot be doubted, but that to discover the truth, we have to doubt everything. When we come to the truth, the truth will be undoubtable.
Srila Prabhupada: But how do you come to the truth if your business is simply doubting? How will you ever stop doubting?
Syamasundara dasa: Well, I cannot doubt that I am, that I exist. That truth is undoubtable. So he proceeds from there to the fact that since I exist, God exists.
Srila Prabhupada: Then his point is that by doubting, we come to a point where there is no more doubt. That is good. Doubt in the beginning, then the truth as the conclusion. But in any case, that doubt must be resolved. I doubt because I am imperfect and because my knowledge is imperfect. So another question is how we can obtain perfection. As long as we are imperfect, there will be doubt.
Syamasundara dasa: He says that even though I am imperfect, there exists perfect knowledge, or a self-conscious awareness of perfect ideas within myself. Knowledge of the perfect is innate within me, and I can know it through meditation.
Srila Prabhupada: That is also acceptable.
Syamasundara dasa: Because I understand that I think, I can establish existence of my soul beyond all doubt.
Srila Prabhupada: Everyone thinks. Everyone is there, and everyone has a soul. There are countless souls, and this has to be accepted.
Syamasundara dasa: What about a blade of grass, for instance?
Srila Prabhupada: Yes, it has a way of thinking. That has to be accepted. It is not that we have souls and that the grass has no soul, or that animals have no souls. Jagadish Candra Bose has proved by a machine that plants can feel and think. "I think, therefore I am" is a good proposition because everyone thinks and everyone exists. There are 8,400,000 species of living entities, and they are all thinking, and they all have individual souls.
Hayagriva dasa: There is a lot of conjecture in Descartes concerning the location of the soul. In his Meditations, he writes: "Although the soul is joined to the whole body, there is yet a certain part in which it exercises its functions more particularly than in all the others; and that is usually believed to be the brain, or possibly the heart; the brain, because it is with it that the organs of sense are connected, and the heart because it is apparently in it that we experience the passions." Descartes then goes on to conclude that the soul is situated in a small appendage of the brain called the pineal body.
Srila Prabhupada: This speculation means that he has no definite information. Therefore we have to accept God's instructions. In Bhagavad-gita, Krsna specifically states:
hrd-dese 'rjuna tisthati
"The Supreme Lord is situated in everyone's heart, O Arjuna." (Bg. 18.61) There are two kinds of isvaras, controllers. One is the individual living entity, the jiva, and the other is the Supreme Living Being, the Paramatma, or Supersoul. From the Vedas, we understand that both are sitting together within this body, which is compared to a tree. Both the Supersoul and the individual soul are living within the heart.
Hayagriva dasa: But at the same time, does