Cultura is the third core element of Loricism. It is Latin for "culture." If Ingenium is about development of the individual to achieve self-mastery, and Communicatio Ratio is about being able to use reason, this is creating a culture of individual character and reason. Since Loricism aims to create a culture of reason and justice, being able to communicate ideas effectively is essential. Cultura focuses a lot on the Justice virtue of Ingenium and being able to share effective ideas with others in order to help them improve themselves.
A good summary of Cultura would be the adage, "A rising tide lifts all ships."