Yes, yes, we are taught to fly in the air like birds, and to swim in the water like the fishes; but how to live on the earth we don’t know.

Maxim Gorky (1868-1936) Russian writer [b. Alexei Maximovich Peshkov]

(Attributed)

Quoting a Russian peasant on progress; cited in Lothrop Soddard, Social Classes in Post-War Europe (1925).

Quoted later by Martin Luther King, Jr., in "The Man Who Was a Fool," Strength to Love (1963): "We have learned to fly the air like birds and swim the sea like fish, but we have not learned the simple art of living together as brothers"; he used the same phrase in his Nobel Peace Prize lecture (1964).

Variant: "Now that we have learned to fly the air like birds, swim under water like fish, we lack one thing—to learn to live on earth as human beings."

Sometimes misattributed to George Bernard Shaw. See here for more information.