"I consider Mr. Morphy the finest chess player who ever existed. He is far superior to any now living, and would doubtless have beaten Labourdonnais himself. In all his games with me, he has not only played, in every instance, the exact move, but the most exact. He never makes a mistake; but, if his adversary commits the slightest error, he is lost." Adolf Anderssen in 1859.
"Morphy not let me." former unofficial world champion Adolf Anderssen, when asked why he not play as brilliantly as usual against Paul Morphy.
"Paul Morphy was the greatest chess player that ever lived...no one ever was so far superior to the players of his time" Dr. Emanuel Lasker, Lasker's Chess Magazine of January 1905, p.127.
"In Paul Morphy the spirit of La Bourdonnais had arisen anew, only more vigorous, firmer, prouder... Morphy discovered that the brilliant move of the master is essentially conditional not on a sudden and inexplicable realisation, but on the placing of the pieces on the board. He introduced the rule: brilliant moves and deep winning manoeuvres are possible only in those positions where the opponent can be opposed with an abundance of active energy... From the very first moves Morphy aimed to disclose the internal energy located in his pieces. It was suddenly revealed that they possess far greater dynamism than the opponent's forces." Emanuel Lasker.
"Morphy's principal strength does not rest upon his power of combination but in his position play and his general style....Beginning with la Bourdonnais to the present, and including Lasker, we find that the greatest stylist has been Morphy. Whence the reason, although it might not be the only one, why he is generally considered the greatest of all." José Raúl Capablanca, in Pablo Morphy by V. F. Coria and L. Palau.
"[I play in] the style of Morphy, they say, and if it is true that the goddess of fortune has endowed me with his talent, the result [of the match with Emanuel Lasker] will not be in doubt. The magnificent American master had the most extraordinary brain that anybody has ever had for chess. Technique, strategy, tactics, knowledge which is inconceivable for us; all that was possessed by Morphy fifty-four years ago." José Raúl Capablanca.
"...Morphy, the master of all phases of the game, stronger than any of his opponents, even the strongest of them..." Alexander Alekhine, in Shakmatny Vestnik, January 15, 1914.
"To this day Morphy is an unsurpassed master of the open games. Just how great was his significance is evident from the fact that after Morphy nothing substantially new has been created in this field. Every player- from beginner to master- should in this praxis return again and again to the games of the American genius." Mikhail Botvinnik.
"A popularly held theory about Paul Morphy is that if he returned to the chess world today and played our best contemporary players, he would come out the loser. Nothing is further from the truth. In a set match, Morphy would beat anybody alive today... Morphy was perhaps the most accurate chess player who ever lived. He had complete sight of the board and never blundered, in spite of the fact that he played quite rapidly, rarely taking more than five minutes to decide a move. Perhaps his only weakness was in closed games like the Dutch Defense. But even then, he was usually victorious because of his resourcefulness." Bobby Fischer, 1968.
"Morphy, I think everyone agrees, was probably the greatest genius of them all." Bobby Fischer, 1992
"We also remember the brilliant flight of the American super-genius Paul Morphy, who in a couple of years (1857-59) conquered both the New and the Old Worlds. He revealed a thunderous blend of pragmatism, aggression and accurate calculation to the world -- qualities that enabled America to accomplish a powerful spurt in the second half of the 19th century." Garry Kasparov (2003). On My Great Predecessors. Gloucester Publishers plc. Vol. 1, p. 6.
"What was the secret of Morphy's invincibility? I think it was a combination of a unique natural talent and brilliant erudition. His play was the next, more mature stage in the development of chess. Morphy had a well-developed 'feeling for position', and therefore he can be confidently regarded as the 'first swallow' - the prototype of the strong 20th century grandmaster." Garry Kasparov (2003). On My Great Predecessors. Gloucester Publishers plc. Vol. 1, p. 43.