According to Canon Law 1325:
Can. 1325 Crass, supine, or affected ignorance can never be considered in applying the prescripts of cann. 1323 and 1324; likewise drunkenness or other disturbances of mind cannot be considered if they are sought deliberately in order to commit or excuse a delict, nor can passion which is voluntarily stimulated or fostered.
Can. 1323 and Can. 1324 describe who can be punished for lawbreaking. For example, by excommunication.
According to Wikipedia, “When little or no effort is made to remove ignorance, the ignorance is termed crass or supine”.
Most Catholics today are poorly catechized and unfortunately ignorant of much of Canon law and the penalties contained therein. How much responsibility to individual Catholics have to educate themselves about what offenses are excommunicable or even that the concept of excommunication latae sententiae exists at all? For example, if a baptized Catholic commits an excommunicable offense and has never heard of excommunication latae sententiae, would the excommunication apply to him or her? Or if he or she knew something was excommunicable but thought the only kind of excommunication was ferendae sententiae, or imposed excommunication, would the latae sententiae excommunication apply to that person?
In other words, how much responsibility do Catholics have to know about these things, and when does failing to find out cross the line into supine or crass ignorance?