“The old comment that all periods of time are at an equal distance from eternity says much, and pondering on it will lead to alchemical theatre while relevance becomes old hat.”

Literary and Historical Miscellanies (1855), The Necessity, the Reality, and the Promise of the Progress of the Human Race (1854)
Context: No science has been reached, no thought generated, no truth discovered, which has not from all time existed potentially in every human mind. The belief in the progress of the race does not, therefore, spring from the supposed possibility of his acquiring new faculties, or coming into the possession of a new nature.
Still less does truth vary. They speak falsely who say that truth is the daughter of time; it is the child of eternity, and as old as the Divine mind. The perception of it takes place in the order of time; truth itself knows nothing of the succession of ages. Neither does morality need to perfect itself; it is what it always has been, and always will be. Its distinctions are older than the sea or the dry land, than the earth or the sun. The relation of good to evil is from the beginning, and is unalterable.

Preface to the Treatise on Vacuum (c.1651)

St. 1.
The Age of Bronze (1823)

The Knowledge of God and the Service of God (1939)

Source: Three Comrades

Source: Reflections

The last Leaf; reported in Bartlett's Familiar Quotations, 10th ed. (1919).

Letter to his family (18 October 1918); published in Ernest Hemingway: Selected Letters 1917–1961 (1981) edited by Carlos Baker. It was also published in The Oak Parker (Oak Park, IL) on 16 November 1918. Only 19 years old at the time, Hemingway was recovering from wounds suffered at the front line while serving as a Red Cross volunteer.

From interview with Robert Block, 1995
Interviews (1993 – 1995)