evidence: - As discussed in this entry from The Quote Investigator, the earliest published attribution of a similar quote to Einstein seems to have been in Gestalt therapist Frederick S. Perls' 1969 book Gestalt Theory Verbatim, where he wrote on p. 33: "As Albert Einstein once said to me: 'Two things are infinite: the universe and human stupidity.' But what is much more widespread than the actual stupidity is the playing stupid, turning off your ear, not listening, not seeing." Perls also offered another variant in his 1972 book In and Out the Garbage Pail, where he mentioned a meeting with Einstein and on p. 52 quoted him saying: "Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." [...] - If Einstein said this, he was almost certainly quoting philosopher Immanuel Kant's words from the conclusion to the Critique of Practical Reason (1788), translated in Paul Guyer's The Cambridge Companion to Kant (p. 1) as: "Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above me and the moral law within me."