The antonym of "non-feasance" is "feasance," which refers to the act of doing something or taking action. In other words, "feasance" denotes an affirmative action taken to fulfill one's duty or responsibility. It implies that someone has taken necessary steps to carry out a task or responsibility. The opposite of "non-feasance" does not necessarily mean positive action, but it represents the fulfillment of obligations. Feasance implies that someone is responsibly performing their assigned duties, unlike non-feasance, which means the failure to perform. Therefore, if non-feasance represents neglect or inaction, then "feasance" represents responsibility, activity, performance, and action.