Morphy was an innovator of chess; something like the great great great great great great grandfather of the modern grandmaster. 

Using the same analogy, Kasporov would be one of his many great great great great great great grandchildren.

The progression of any game or art is the same. Without Bach, there would be no Baroque era, and without it, there would be no Classicists like Haydn or Mozart, no Beethoven, the shepherd that lead the people to  Romanticism, and no Stravinky or Rimsky-Korsokov. All of them played a role in the evolution of music. 

Kasparov would have been the chess counterpart of Rimsky-Korsokov while Morphy would have been a Mozart. Their music cannot be compared to each other because of the sheer difference in style in their time periods (20th century vs. classical), and thus, whether one is better than the other is independent of scientific determination and boils down to individual tastes. 

Good point VULPES_VULPES.

Morphy would of tataly crushed Kasparov

it takes a willingness not to accept authority for the sake of authority.