David Lawson included this hearsay reference in Paul Morphy: the Pride and the Sorrow of Chess:

"...in 1874, Paul Morphy, in an offhand conversation (Dubuque Chess Journal of December 1874), expressed the following opinion of Mr. Staunton as a chess master:

     Mr. Staunton's knowledge of the theory of the game was no doubt complete; his powers as an analyst were of the very highest order, his coup d'oeil and judgment of position and his general experience of the chess board, great; but all these qualities which are essential to make a GREAT chess player do not make him a man of GENIUS. These must be supplemented by imagination and by a certain inventive or creative power, which conceives positions and brings them about. Of the faculty (he said) he saw no evidence in the published games of Mr. Staunton.
     In a give position, where there is something to be done, no matter how recondite or difficult the idea, Mr. Staunton will detect it, and carry out the combination in as finished a style as any great player that ever lived, but he will have no agency in bringing about the position.
     Therefore in his best day, Mr. Staunton in his opinion could not have make a successful fight against a man who had the same qualities as himself and who, besides, was possessed of the creative power above mentioned such as were Anderssen of Germany, M'Donnell of England, and La Bourdonnais of France.
     To all that had been said concerning Mr. Staunton personally, his brilliant conversational powers, etc. (he said) he could himself bear witness, as he had the frequent occasions to meet Mr. Staunton in social intercourse.
     As a chess author, he thought, as everybody does, that Mr. Staunton's ability was of the very highest order, and that he had done more for the diffusion and propagation of chess than almost anyone else. As a commenter on games actually played, aside from the personalities, he was at times too prone to indulge in, he stood absolutely without a rival.
     As a player he was entitled to a very high rank indeed, and perhaps he was, as is claimed for him, the ablest player of his day; at the same time he was not prepared to admit that Mr. Staunton possessed to any great degree GENIUS FOR CHESS as he understands the term.