The difference between stupidity and genius is that genius has its limits

We searched Einstein's known corpus — his books such as "The World As I See It" and "Out of My Later Years," his collected papers, published letters, and verified transcripts of his lectures and interviews — and found no primary source for this line, and Alice Calaprice's authoritative "The Ultimate Quotable Einstein" does not verify it either. What tips this beyond a simple unsupported attribution is citable positive evidence of an earlier origin: the joke's core structure traces to Alexandre Dumas fils, who wrote in an 1886 item in "Le Figaro" that "in this world, only genius has limits," and the "Grand Dictionnaire Universel du XIXe Siècle" (1865) carries a French precursor in its entry for "Bêtise." The idea also circulated in English as a general aphorism well before it was hung on Einstein — a 1923 item in "The Judge" ran the form "Genius has its limitations, but stupidity is not thus handicapped." The modern Einstein credit appears only in later compilations and general-interest books (such as John Lloyd and John Mitchinson's 2009 quiz book and various programming manuals), none of which supply a traceable Einstein document. Because a specific, documented earlier origin can be named and the saying demonstrably predates its attachment to Einstein, this is not merely "common but unsupported." On the evidence available, we consider this quotation misattributed.