When asked about the reasons for these drastic changes, she 'pleaded/pled ignorance'. [=she said that she did not know the reasons]
Their decisions were made 'in ignorance of' [='without knowing'] the true nature of the situation.
His racist attitudes were born out of 'ignorance'.
(..) But for that... ...you would need a smuggler. For which we would pay double. Such is the nature of evil. Out there in... ...the vast ignorance of the world... ...it festers and spreads. A shadow that grows in the dark. A sleepless malice as black... ...as the oncoming wall of night. (..)2013 The Hobbit: The Desolation of Smaug