Peace of mind is clearly an internal matter.
It must begin with your own thoughts,
and then extend outward.
It is from your peace of mind
that a peaceful perception of the world arises.

Let me look on the world I see
as the representation of my own state of mind.
I know that my state of mind can change,
and so I also know the world I see can change as well.

from 'Gifts From A Course In Miracles'
ISBN 0-87477-803-4