If the spirit is a shuttle, how can it be complex?

[Spaced]

In what way(s) does declaring the mind to be complex cause the spirit to become complex? Does just the fact that it can be realized in distorted ways cause the spirit itself to be complex?

I think it has to do with the introduction of the veil between the conscious and unconscious aspects of the mind. Prior the the veiling the function of the spirit was a simple movement of light into darkness, the veil allows for more distortion and work with shadow and various shades of grey. I think there's a Ra quote to that effect but I can't seem to find it.