You included no options so the answer will be a bit general.
The Latin suffix <em>-ity</em> is used to describe the degree of the presence of the condition in the word that it is added to. For instance, the word <em>profitable </em>means the condition of making a gain from something. When the suffix <em>-ity</em> is added to it to make it <em>profitability</em>, the meaning changes to the amount of profit or gain that can be made from something.
In this case therefore, if <em>sagacious</em> means wise, <em>sagacity</em> would refer to the amount of wisdom possessed by the subject in question.
