What is the Mind?

It's simple - "Mind" is the common and/or scientific word used to identify the Soul essence.

Our physical body has a "brain" which can perform certain functions to surive on this planet. The essence of any creature is its Soul. This Soul is the 90% of the brain that scientist say we don't use. Remember, Soul is the individual Life Energy or Spirit that we are all a part of.

Let's use the stages of water as an analogy. Ice is the physical body, brain, water is the Mind, and water vapor is the Spirit. All aspects of the same thing.