Is an all volunteer military an army of mercenaries?

Mercenaries fight for the highest bidder and hold no allegiance to anyone; they are private businessmen. An all volunteer army is sworn under oath to defend it's nation, and is a "profession", just like the medical field, engineering field, legal field, manufacturing field, sales, etc. The Soldiers and Sailors (and Airmen & Marines) are employed in the "profession of arms"; the field of military science.