A brilliant Los Angeles attorney, Cates hit the big-time when he became one of the many attorneys to service the Colby family. Knowing all the legal ins and outs, Cates has been called upon by the Colbys time and time again, including Andrew Colby, his daughter-in-law Sable, and his granddaughter Monica. Arthur helped draw up Andrew Colby's will after he became repulsed by the actions of his sons Cecil and Philip. So Arthur came up with legal means to comer anyone who tried to take a piece of the Colby Empire without being a Colby to start with. This came back to haunt Cates when Sable tried to undo Andrew's wishes 01i occasion. First, Sable tried to prove Constance incompetent. Garrett Boydston, a legal mastermind himself, was weary of going up against Cates. Next, Sable tried to take the very house that Andrew Colby built away from Jason and Constance. Later, Cates counseled Monica about her rights as a mother who gave up her child for adoption. Always resourceful, respected, and ever scheming, Arthur Cates is one not to underestimate.