Leaving Some Foot Prints

"The Edwardian Apostles [an advanced and select discussion group at Cambridge University in England in 1905] were ambitious men who wanted their work to endure in memory. They even had a code-word, 'footprints', for the guiding-marks which they hoped to leave for posterity. The best test of the value of work, they believed, is that it continues to please or impress future ages. Bertrand Russell once recounted to G. H. Hardy a distressing dream in which he stood among the book stacks of Cambridge University two centuries in the future. A librarian was winnowing the shelves, taking down books in turn, glancing at them, restoring them to their places or dumping them into an enormous bucket. Finally, he reached three volumes which Russell recognized as the last surviving copy of his Principia Mathematica. He took down one of the volumes, turned over a few pages, seemed puzzled by what he saw, shut the volume, balanced it in his hand and hesitated: Russell presumably awoke with a shuddering cry, for the devaluation of their work, or the absence of footprints, was the Apostles' nightmare."
- Richard Davenport-Hines, Universal Man: The Lives of John Maynard Keynes, 2015, p.52   
John Maynard Keynes (1883-1946) is a famous and influential economist.