And then, jealousy means lowering both myself and her," he told himself as he went into her boudoir; but this dictum, which had always had such weight with him before, had now no weight and no meaning at all.
There are no more uses of "dictum" in the book.
Show samples from other sources
Love whom you will but marry your own kind was a dictum amounting to instinct within her.
Harper Lee -- Go Set a Watchman
I don’t even remember where I learned that childhood rhyme or the dictum that demanded you scratch your head every time you heard a siren, lest the next siren be for you.