Inquisition persecution forced converts into absolute silence as self-defense

Evidence

This one class apart (whose special status in this respect arises from the highly privileged position of the noble within Spanish society at this time), any ex-Muslim had good reason to keep silent about his or her own Muslim past or, in later generations, about the Muslim past of his forebears. The Inquisition had procedures designed to ferret out information about individuals with a Muslim background, and against these the only effective form of self-defense and of defense of the local community was absolute silence. The modern investigator has to rely almost exclusively on written documents—there are hardly any useful techniques able to exploit other evidence. So we know about Muslims and crypto-Muslims because of what they wrote themselves or because of what others (almost always their enemies) wrote about them: aljamiado manuscripts on one hand, the contents of Inquisitorial processes, on the other. — L. P. Harvey, Muslims in Spain, 1500 to 1614, 1156