The subject of this paper is to examine ‘the harmony argument’, which is considered as a materialist understanding of soul in Plato's Phaedo (86a-94e), and to evaluate the 'eliminative materialism', which is a materialist philosophy of mind in the contemporary period. To do this, first of all, the main points of the harmony argument will be examined. The harmony argument is provided by Simmias in the dialogue. The harmony argument is advanced by Simmias in the dialogue. According to him, the harmony in the sound of a tuned lyre is something invisible and immaterial, just like the soul, while the strings of the lyre are corporeal, composite. However, when the corporeal string disappears, the harmony also disappears. Why not consider the same for the soul and the body? When we look at the contemporary philosophy of mind, it can be said that especially materialist philosophies of mind are in demand and that they reduce the mind to the brain, just as harmony is reduced to string in the example of the lyre above. Eliminative materialism, which is discussed in this paper, is at the far end of this issue and states that the mind is completely the brain and that the mind can be eliminated. If we consider the argument of harmony with the claims of eliminative materialism, according to them, there is nothing but sound and string, and movements in sound and string are called harmony in an unscientific way. Since there is no such thing as harmony, this concept will disappear as science progresses about the lyre and its strings. Philosophy of mind is a very current and important sub-field of philosophy as a field of study, considering topics such as artificial intelligence in the contemporary period. It can be thought that the philosophy of religion, in which subjects such as metaphysics and spirit are studied, can point to important places in this field, especially when it is considered that science is handled with a materialist way today. This paper, it is aimed to compare the harmony argument in the Phaidon dialogue, which is one of the most basic texts on the subject that the soul is a substance separate from matter, with the elective materialism, which is one of the contemporary theories, and to present the answers that can be given to materialism in this regard. While doing this, the text of the dialogue was analyzed and examined in a comparative way with contemporary thoughts. As a result, it was seen that three important issues arise in Socrates' answer to the harmony argument. According to Socrates (i) the soul exists before the body, and harmony emerges after the lyre and strings. (ii) The soul is active on the body, it can oppose the body. But harmony is not active on lyre and strings, it can only follow them. (iii) Spirit is simple, there is no such thing as being more or less spirit. But the harmony may be less or more. Considering these claims of Socrates, it has been seen that the second view, which we can call the problem of free will, is an important objection for eliminative materialism. It has hardly dealt with the other two issues above. However, it was concluded that while denying the subjective experiences of human beings, eliminative materialism did not fully base it, and it was criticized on this subject in the philosophy of mind.