How often and easily we toss that word into conversation. Hate is a terrible emotion. Through the centuries others have expressed thoughts on hate. Several linked fear and hate. Much later a similar description is found in Robert Graves writings.
Hate is fear, and fear is rot that cankers root and fruit alike.
Roman historian Tacitus was born before Christ but lived into the early Christian era. He put a little different spin on why we hate. It is human nature to hate those whom we have injured. Our homespun poet James Russell Lowell added another explanation to why we hate. Folks never understand the folks they hate.