Not sure it's a motto, but this is a quote that really helped me when I fell out with someone. I try to keep it in mind in other unfavorable situations.
"For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring." --Carl Sagan
"For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring." --Carl Sagan
"For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring." - Carl Sagan