La trattazione di Gai 3.140-141 sul pretium nella compravendita, tra 'regulae' e ius controversum

The text of Gaius’ Institutes concerning the price of a sale contains a curious peculiarity. Gaius first of all reports the requisites of the price in the form of peremptory rules, but soon afterwards he indicates as consequence (nam...) a contrast of views: some jurists admit the relevance of a sale which doesn’t observe these requisites. The Author suggest that the (merely) apparent contradiction is an example of the particular approach ‘operativo-cautelare’ of the whole work: Gaius wants to point out, in a ‘warning perspective’, the conditions to be complied so that the effect of the legal transaction is sure and beyond dispute, by distinguishing from the case in which the effect is uncertain.