demand, necessity, expediency, requisition, needed, desired, demanded, inclined

according to age

by way of loyalty

habitually

the demand of one's age

exigency of the situation, according to the requirements of the situation

intellectually, wittingly

the demands of understanding

need of the hour, need of/for time

naturally

humanly

as per one's nature

by way of man kind

according to justice

as per convention, conventionally

desirous, requiring, demanding, exacting, demanding

to demand, require, exact, to impel, or urge (to)

according to the requirements of, in consequence, through, owing to, because of, for the reason of