Arizona Revised Statutes § 1-201 states:
The common law only so far as it is consistent with and adapted to the natural and physical conditions of this state and the necessities of the people thereof, and not repugnant to or inconsistent with the Constitution of the United States or the constitution or laws of this state, or established customs of the people of this state, is adopted and shall be the rule of decision in all courts of this state.

Malone v. Sullivan, 605 P. 2d 447 - Ariz: Supreme Court 1980 states:
A.R.S. §§ 12-601 and 602 provide for a change of name. This statute is in aid of the common law rule that absent fraud or improper motive, a person may adopt any name he or she wishes. Laks v. Laks, 25 Ariz. App. 58, 540 P.2d 1277 (1975)

Laks v. Laks, 540 P. 2d 1277 - Ariz: Court of Appeals, 2nd Div. 1975 states:
Under the common law a person had a right to change his name without legal formality. State v. Carroll, 21 Ariz. App. 99, 515 P.2d 1197 (1973). In the absence of a statutory restriction, one may lawfully change his name without resort to any legal proceedings. Mark v. Kahn, 333 Mass. 517, 131 N.E.2d 758 (1956). Statutes such as A.R.S. Sec. 12-601 and Sec. 12-602 merely affirm and are in aid of the common law rule. They do not repeal the common law by implication or otherwise, but afford an additional method of affecting a name change. Re Taminosian, 97 Neb. 514, 150 N.W. 824 (1915); Smith v. United States Casualty Co., 197 N.Y. 420, 90 N.E. 947 (1910); Laflin & Rand Powder Co. v. Steytler, 146 Pa. 434, 23 A. 215 (1892).