Dualism is a philosophical view that states that reality is made up of two parts that cannot be reduced to one another. The crucial point of dualism is demonstrated as follows: if the justification of the universe is understood to be necessary as something understandable, these two parts must be reconciled. Dualism is one of the fundamental elements of metaphysics.
This discussion is that the mind and the body are separate and that they have no connection. But that was a theory of times gone by, not applicable to our current reality, because the mind and the body are entirely interconnected and work together all the time.