Albert Einstein's remark is most often cited as:
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.
But there is some question that it is properly attributed to Einstein.
One credible-looking discussion of the matter asserts that Frederick S. Perls, in his
Ego, Hunger, and Aggression: a Revision of Freud’s Theory and Method, says:
"As modern times promote hasty eating to a large extent, it is not surprising to learn that a great astronomer said: “Two things are infinite, as far as we know – the universe and human stupidity.” To-day we know that this statement is not quite correct. Einstein has proved that the universe is limited."
Later, Perls, in
Gestalt Therapy Verbatim, says:
"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."
But in Perls'
In and Out the Garbage Pail, he says:
"I spent one afternoon with Albert Einstein: unpretentiousness, warmth, some false political predictions. I soon lost my self-consciousness, a rare treat for me at that time. I still love to quote a statement of his: 'Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe.' "
Sadly, Perls does not favor us with any further developments of what Einstein
really said, or where, or to whom.
Reference:
http://quoteinvestigator.com/2010/05/04/universe-einstein/
Best regards,
Doug