For thousands of years humans have defended themselves from harm by others. But many have proceeded to regularly harm themselves. They have actively searched for substances to ingest, inhale, inject and apply which may give them some immediate relief but damage or destroy their lives over time.
Why do these humans so beat up on their own bodies? Obviously, they know that damaging behaviors have serious consequences, both immediately and in the long run. Why have health care professionals had such a hard time convincing people “to do no harm” to themselves? The persistence of partial self-immolation is unremitting.
What’s different about recent centuries from prior millennia is that addiction, masochism, slow-motion suicide have become big business. Now there are huge profits to be made in seducing, tempting or deceiving people at all ages to spend money to harm themselves.