"No problem can withstand the assault of sustained thinking."
"You and I are not what we eat; we are what we think."
"The trouble with most people is that they think with their hopes or fears or wishes rather than with their minds."
"Thinking is like loving and dying. Each of us must do it for himself."
"What was once thought can never be unthought."
Carl J. Friedrich
"A man's life is what his thoughts make of it."
"It is the power of thought that gives man power over nature."
Hans Christian Anderson
"Thinking more than others about our own thoughts is not self-centeredness. It means that if asked what's on our mind, we are less likely to mention being aware of the world around us, and more likely to mention our inner reflections. But we are less likely to mention thinking about other people."
Elaine N. Aron
"The positive thinker sees the invisible, feels the intangible, and achieves the impossible."
"You must not allow yourself to dwell for a single moment on any kind of negative thought."