Illiteracy and Ignorance

At the end of class last week, I found myself feeling uncomfortable with the way the class was using the term "illiterate."  As we are all working to expand our definitions of literacy, I think it is important to keep in mind how we're using related terms.  I really like the idea that literacy goes beyond the ability to read and write to encompase having knowledge or competency in an area but does that mean that being illiterate is the opposite of that?  While I'm comfortable with the fact that I am not literate in all areas, I'm not comfortable with the idea that not being literate in an area means that you are illiterate.  I'm also interested with the connection between illiteracy and ignorance.  Are they connected?  If only in the sense that both words seem to have very negative connotations with me despite the fact that they shouldn't be neccessarily negative.  For me, ignorance is not knowing and I think given my previous definition of literacy one could say that being illiterate is not knowing.  However, I think illiterate is used in a much broader sense than ignorance.  For example, I think the way I have been thinking about the terms, one can easily be ignorant about part of a culture or lifestyle or any number of things.  However, if you are illiterate, it isn't just one part of a culture or lifestyle but its the whole culture.  I think it is easiest to understand in terms of language.  To be literate, one must know a language - how to read and write in that language but also nuances in terms of tone, when certain words are used instead of others, knowing a discourse.  To be illiterate is to not know any language.  This is why I do not think the two work as opposites of each other.  It is possible to be literate in more than one language but not possible to be illiterate if you know at least one language.  To be ignorant is to know part of a language.  Maybe you know how to read and write but are not able to discern nuances like sarcasm or understand when you are speaking formally or informally.  Perhaps these defnitions don't leave enough grey area, but for me they establish a base with which to develop better ideas of all these terms.