Paul Charles Morphy "The Pride and Sorrow of Chess", is considered to have been the greatest chess master of his time, an unofficial World Champion and, is considered by many, including some grandmasters (see below) the greatest chessplayer who has ever lived.

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• "Chess is eminently and emphatically the philosopher's game." (The exact quote is "It is eminently and emphatically the philosopher's game," with 'Chess' as the antecedent of 'It'.)
  • from Paul Morphy's speech at the New York Chess Club Testimonial held in his honor, May 25, 1859.

• "I am more strongly confirmed than ever in the belief that the time devoted to chess is literally frittered away."
  • Letter to Daniel Fiske, February 4, 1863.

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• "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, quoted by Frederick Edge in 1859

• "Morphy will not let me." ~ former unofficial world champion Adolf Anderssen, when asked why he did not play as brilliantly as usual against Paul Morphy

• "...Morphy was stronger than anyone he played with, including Anderssen" ~ Wilhelm Steinitz, International Chess Magazine 1885.

• "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.

• "Reviewing the history of chess from La Bourdonnais to the masters of our day right up to Lasker, we discover that the greatest stylist was Morphy. He did not look for complicated combinations, but he also did not avoid them, which really is the correct way of playing... His main strength lay not in his combinative gift, but in his positional play and general style. Morphy gained most of his wins by playing directly and simply, and it is this simple and logical method that constitutes the true brilliance of his play, if it is considered from the viewpoint of the great masters." ~ José Raúl Capablanca

• "[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

• "How much more vivid, more rich does the figure of Morphy appear before us, how much clearer does the secret of his success and charm become, if we transfer ourselves in our thoughts to that era when he lived and created, if we take the trouble to study, only a little, his contemporaries! Then...in London and in particular in Paris, where the traditions of Philidor were still alive, where the immortal creations of La Bourdonnais and McDonnell were still in the memory, at that time, finally, when Anderssen was alive, and with brilliance alone it was hardly possible to surprise anyone. The strength, the invincible strength of Morphy- this was the reason for his success and the guarantee of his immortality!" ~ Alexander Alekhine

• "...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

• "If the distinguishing feature of a genius is that he is far ahead compared with his epoch, then Morphy was a chess genius in the complete sense of the word." ~ Max Euwe

• "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

• "There is no doubt that for Morphy chess was an art, and for chess Morphy was a great artist. His play was captivated by freshness of thought and inexhaustible energy. He played with inspiration, without striving to penetrate into the psychology of the opponent; he played, if one can express it so, "pure chess". His harmonious positional understanding; the pure intuition, would have made Morphy a highly dangerous opponent even for any player of our times." ~ Vassily Smyslov

• "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

• "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. ISBN 1857443306.

• "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. ISBN 1857443306.

• "[Paul Morphy] just appeared from nowhere and it was only thirty or forty years later that people understood why he was so dominant. His understanding of chess at [that] point was at least forty years ahead of the rest of the world. For the era in which he lived the kind of chess he played was unbelievable." ~ Current World Chess Champion Viswanathan Anand, Interview with Shobha Warrier on his ten favorite chess players

• "Morphy was the first positional player who, unlike his Romantic rivals, understood the strategic basis for attack. He wrote nothing more than a few game notes and played fewer than seventy-five serious games. But his exploitation of open lines prepared the way for Steinitz's scientific treatment of closed positions and the era of modern chess." ~ Richard Réti

• "After the passage of a century, Morphy still remains the most glamorous figure that has ever appeared in the chess world." ~ Edward Lasker (in The Adventure of Chess, 2nd Edition, New York, 1959)

• "Genius is a starry word; but if there ever was a chess player to whom that attribute applied, it was Paul Morphy." ~ Andrew Soltis (in Golombek's Encyclopedia of Chess, New York, 1977)

• "It has been truly said that Morphy was at once the Caesar and the Napoleon of chess. He revolutionized chess. He brought life and dash and beauty into the game at a time when an age of dullness was about to set in and he did this at a stroke. Then he quit forever. Only two years from the beginning to the end. The negotiations for some modern matches have taken that long!" ~ J. A. Galbreath (American Chess Bulletin, October, 1909)

• "La Bourdonnais [a great player, b. 1795 - d. 1840] died young in London, and the goddess of Chess, Caissa, very much grieved, mourned for him and forgot to inspire the masters with her sunny look. A dreary time then came over the Chess world. The masters played a dry style, without enthusiasm, without imagination, without force, and the Chess fraternity was full of the wrangles of the mediocrities. It is true, the goddess soon repaired her omission. She flirted – Goddess! pardon me this vulgar expression, but the coarse human language does not know the shades of meaning such as undoubtedly you would be able to express by means of Chess pieces – she flirted, I beg to say, with the English historian [and renowned authority on Shakespeare, whose name has been given to the style of Chess pieces we now use] Staunton and prevailed upon him to organize in 1851 an international chess tournament in London, during the great International Exposition of that year. And then – fickle Goddess – she gave her love to a young mathematician, the German Anderssen, and inspired him to superb combinations. And then -- oh the weakness of her – she spied with her great sunny eye in far distant Louisiana a boy, highly talented; she forgot all about Anderssen, guided the steps of the young American, fell in love with him, introduced him to the world and said triumphantly: “Here is the young Paul Morphy, stronger and greater than master ever was.” And the world listened and applauded and cried “Hurrah for Paul Morphy, the King of Chess!”
  
  In Paul Morphy the spirit of La Bourdonnais had arisen anew, only more vigorous, firmer, prouder. He never formed columns of Pawns for the purpose of assaulting a firm position as Philidor had taught, he always fought in the centre, only a few Pawns in front, and if he needed the lines open, he sacrificed even these few advanced posts. Should the adversary make use of Philidor’s maxims, Morphy’s pieces occupied the gaps in the oncoming mass of Pawns and opened up an attack, so as to leave the enemy no time for slow, methodical maneuvering. Paul Morphy fought; on good days and on bad days, he loved the contest, the hard, sharp, just struggle, which despises petted favourites and breeds heroes.
  
  But then the Civil War broke out in the United States and broke the heart and mind of Morphy.
  
  ...When Paul Morphy, despairing of Life, renounced Chess, Caissa fell into deep mourning and into dreary thoughts. To the masters who had come to ask her for a smile she listened absent-mindedly, as a mother would to her children after her favourite had died. Therefore, the games of the masters of that period are planless; the great models of the past are known, and the masters try to follow them and to equal them, but they do not succeed. The masters give themselves over to reflection. One of them reflects a long time and intensely on Paul Morphy, and gratefully Caissa encourages him; and the greatest landmark in the history of Chess is reached: William Steinitz announces the principles of strategy, the result of inspired thought and imagination...
  
  ...Principles, though dwelling in the realm of thought, are rooted in Life. There are so many thoughts which have no roots and these are more glittering and more seducive [sic] than the sound ones. Therefore, in order to distinguish between the true and the false principles, Steinitz had to dig deep to lay bare the roots of the art possessed by Morphy. And when Steinitz after hard work had bared these roots, he said to the world: Here is the idea of Chess which has given vitality to the game since its invention in the centuries long past. Listen to me and do not judge rashly, for it is something great, and it overpowers me...
  
  ... The world would have benefitted if it had given Steinitz a chance. He was a thinker worthy of a seat in the halls of a University...And I who vanquished him must see to it that his great achievement, his theories should find justice, and I must avenge the wrongs he suffered..." ~ former world chess champion Dr. Emanuel Lasker (1925 (in German), Dover edition (in English): 1960). Lasker's Manual of Chess. Dover Publications, p. 186-7. ISBN 0486206408.