The Power of Positive Thinking of followers testified that Peale’s message changed their lives for the better and represented the best combination of faith and pragmatism.” This is evidenced by the popularity of Peale's book, which sold more than 5 million copies worldwide and was eventually translated into over 40 languages. In addition, Peale was close friends with American presidents Eisenhower and Nixon, both of which highly regarded his positive thinking teachings. Countless others accredited "The Power of Positive Thinking" for their success in overcoming obstacles including George Foster, of the Cincinnati Reds, Rev. Robert Schuller, founder and pastor of the Crystal Cathedral in Garden
The Power of Positive Thinking also condemned Peale's methods in his book, "Authentic Happiness". He writes that, “positive thinking often involves trying to believe upbeat statements such as 'Every day, in every way, I’m getting better and better,' in the absence of evidence, or even in the face of contrary evidence.” Seligman continues his critique saying, “if you can manage the feat of actually believing these sorts of statements, more power to you. Many educated people, trained in skeptical thinking, cannot manage this kind of boosterism.” Similarly, Donald Meyer, in his book "The Positive Thinkers", critiques the effectiveness of Peale's techniques saying that Peale always