The ass will carry his load, but not a double load; ride not a free horse to death. – Miguel de Cervantes, Don Quixote

Men are better when riding, more just and more understanding, and more alert and more at ease and more under-taking, and better knowing of all countries and all passages; in short and long all good customs and manners cometh thereof, and the health of man and of his soul. – Attributed to Edward Plantagenet

Horses lend us the wings we lack. – Author Unknown