Resolution will sometimes relax, and diligence will sometimes be interrupted; but let no accidental surprise or deviation, whether short or long, dispose you to despondency. [ Johnson ]

Aim at perfection in everything, though in most things it is unattainable; however, they who aim at it, and persevere, will come much nearer to it than those whose laziness and despondency make them give it up as unattainable. [ Chesterfield ]

True hope is based on energy of character. A strong mind always hopes, and has always cause to hope, because it knows the mutability of human affairs and how slight a circumstance may change the whole course of events. Such a spirit, too, rests upon itself, it is not confined to partial views, or to one particular object. And if at last all should be lost, it has saved itself, its own integrity and worth. Hope awakens courage, while despondency is the last of all evils, it is the abandonment of good, the giving up of the battle of life with dead nothingness. He who can implant courage in the human soul is the best physician. [ Von Knebel (German), Translated by Mrs. Austin ]