This phrase consists of denial coupled with singular ablative of the participle present of the Latin verb obsto - as - are, obstans obstantis, which means prevent or impede and therefore to the letter the phrase means not blocking, not be obstacle. The Academy distinguishes 2 values in it: adverbial phrase, usually between commas, means, however; for example: we are in the winter, however, yesterday was hot. Prepositional phrase which means despite, followed by a noun, infinitive or a preceded by the conjunction that clause.
