This quote by Arthur M. Schlesinger, Jr. talks to the concept that it is frequently easier to judge the actions of besides it is to judge our own. It implies that when reviewing a circumstance, it is easy to see what the best strategy must have been, but it is typically much more difficult to make the best choice in the minute. This quote suggests that hindsight is 20/20, and that it is simple to be righteous in retrospection. It is a pointer that we must strive to make the right choices in the present, even if it is challenging, due to the fact that it will be much easier to evaluate our actions in the future.
"Nature gives to every time and season some beauties of its own; and from morning to night, as from the cradle to the grave, it is but a succession of changes so gentle and easy that we can scarcely mark their progress"