Civilization is not inimical to health and long life. In fact, the contrary is true, for as the people advance they learn to master the forces of nature and with these forces under control they are able to lead better, healthier lives; but if they become too soft and luxurious, there is decay of moral and physical fiber. Civilization is favorable to long life so long as the people are moderate and live simply, but when it degenerates to sensuous softness, individual and racial deterioration ensue. Too generous a supply of food, too little physical activity and packed food are some of the luxuries which are generally introduced with civilization.
Which of the following most accurately summarizes the opinion of the author in the text?