Simmias suggests an analogy between the relationship between the soul and the body on the one hand, and the relationship between the attunement of the strings of a musical instrument and the instrument itself on the other hand. Like the soul, the attunement of a musical instrument is invisible, incorporeal and divine, and like the body, the instrument itself is corporeal, composite, and earthly. Just as the attunement of an instrument exists as a result of the instrument itself being held together at the right tension and in the right way, the soul exists in the body through the body’s being properly assembled. And if destroying a musical instrument can destroy the attunement of the instrument, why can we not say that destroying a body can destroy the soul that is in it?

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Simmias’ objection comparing the soul to the attunement of a musical instrument is closely linked to Pythagorean thought. The Pythagoreans believed in the divinity of music, and in the notion that the motion of the celestial spheres is dictated by perfect harmonies. It is natural, then, for a Pythagorean like Simmias to think of the soul as a harmony. This idea brings in a different view of the soul altogether. In Socrates’ account, the soul is something distinct from the parts of the human body, something that enters the body and imbues it life, but that can exist independently of it. For Simmias, the soul is not a distinct entity so much as the force by which all the parts of the body are held together and through which all the parts of the body are related. The soul gives the body life, but has no life independent of the body, in this view. Thus, the soul cannot exist without the body.

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