Unlike sins of (where we don't know better) or sins of passion (where our emotions overwhelm our reason), malitia is characterized by "willing viciousness". It is a sin committed out of a certain "malice" or a habit of vice.
Below is a blog post exploring this concept based on the scholarly work of Ashley Dressel and traditional Thomistic philosophy. Choosing the Shadow: Understanding the Concept of Malitia malitia
In our daily lives, we often attribute wrongdoing to a lack of information or a momentary lapse in judgment. We say, "I didn't know," or "I wasn't thinking." But what happens when someone knows exactly what the "good" choice is—and chooses the opposite anyway? Unlike sins of (where we don't know better)
In a world that often prizes "knowing" above all else, malitia reminds us that "doing" is a matter of the heart and the will. Choosing the good isn't just about having the right map; it’s about having the will to walk the path. Choosing the Shadow: Understanding the Concept of Malitia