'Bouvier's Law Dictionary' (1914 ed.), is "a term used to indicate a certain class of contractual obligations recognized by the law which are imposed upon a person without his consent and without regard to any act of his own."


This is distinguished from a recusable obligation which, according to Bouvier, arises from a voluntary act by which one incurs the obligation imposed by the operation of law.


The voluntary use of private credit is the condition precedent which imposes the irrecusable obligation to file a tax return.


If private credit is not used or rejected, then the operation of law which imposes the irrecusable obligation lies dormant and cannot apply.