When I synchronize two switching power supplies, one is the master and one is the slave.

The bible speaks of slaying everyone in cities conquered by the Israelites. I believe exceptions were made to take a few slave girls.
Slavery, the humane alternative to slaughter.

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps