Mind cannot exist without matter, indeed mind is of matter, IN matter. Mind is sustained by matter. Mind and matter are equal, as they rely upon the other. However, the effects of the mind are greater, leading to the incorrect belief that mind is greater than matter. One can only see the effects of the mind through the reaction that matter supplies (matter of course being physical entities).
However, mind has no physical form, apart from that of its secondary external state - matter (the mind itself being the primary internal state). This cannot be physically proven. However, the mind is inconsistent all the time, and the effects of mind can