In all epochs of the world's history, we shall find the Great Man to have been the indispensable savior of his epoch;—the lightning, without which the fuel never would have burnt. The History of the World, I said already, was the Biography of Great Men.
 Thomas Carlyle, On Heroes, Hero-Worship, and The Heroic in History (1841). copy citation

Context

“No sadder proof can be given by a man of his own littleness than disbelief in great men. There is no sadder symptom of a generation than such general blindness to the spiritual lightning, with faith only in the heap of barren dead fuel. It is the last consummation of unbelief. In all epochs of the world's history, we shall find the Great Man to have been the indispensable savior of his epoch;—the lightning, without which the fuel never would have burnt. The History of the World, I said already, was the Biography of Great Men. Such small critics do what they can to promote unbelief and universal spiritual paralysis: but happily they cannot always completely succeed. In all times it is possible for a man to arise great enough to feel that they and their doctrines are chimeras and cobwebs.” source