You can take a thousand steps, each the same way, but
step 1,001 results in an injury. How is it you can scientifically
quantify force, but not quantify how a person is damaged?
People don’t live in a controlled environment. A pebble, a tiny
twitch, an unconditioned impression, a life is forever changed.
“The safest and most suitable form of penance seems to be that which causes pain in the flesh but does not penetrate to the bones, that is, which causes suffering but not sickness. So the best way seems to be to scourge oneself with thin cords which hurt superficially, rather than to use some other means which might produce serious internal injury.”
Quotatation from Saint Ignatius of Loyola, Spiritual Exercises