S. Austin Allibone, comp. Prose Quotations from Socrates to Macaulay. 1880.
Constancy
I must confess, there is something in the changeableness and inconstancy of human nature that very often both dejects and terrifies me. Whatever I am at present, I tremble to think what I may be. While I find this principle, how can I assure myself that I shall be always true to my God, my friend, or myself? In short, without constancy there is neither love, friendship, nor virtue in the world.
It is not to be imagined how far constancy will carry a man; however, it is better walking slowly in a rugged way than to break a leg and be a cripple.
Constancy is such a stability and firmness of friendship as overlooks and passes by lesser failures of kindness, and yet still retains the same habitual good will to a friend.