If Carley is still out there answering questions -

We want our students to be critical and to question sources of information.  Do you ever worry about going too far?  When you discuss looking critically at Migrant Mother and what the agenda of the photographer might have been or how even something true can be arranged as propaganda.  Are you ever worried you'll erode the idea of truth and objectivity and feed into some of the objectives of rising fascist ideologies?  How do you put up guard rails to keep " Question everything " from turning into " Nothing can be trusted. " 

Wineburg shares the British Royal Society's motto Nullius in verba ("take nobody's word for it') as a way to help students approach historical/critical thinking. I think this is a great way to encourage students to approach critical thinking without feeding into a complete erosion of truth. By encouraging them to ask questions, seek motivation of a source creator (as in the example you gave), and consider context, it's less about eroding the truth and more about uncovering the truth of the creator (ie. positionality or perspective).

I also think Crissy's (How do we know what we know? video) idea of introducing the professions that uncover and interpret sources of the past, the training they have, etc. helps students establish a process of the questions they ask and the research they perform to decide who they might trust.

As a side note, Lynn Hunt (History: Why it Matters) and Sarah Maza (Thinking About History) both do a great job of examining whether or not objectivity in history is even possible from the perspective of professional historians. Hunt's is a particularly quick read and very thought provoking.

Wineburg shares the British Royal Society's motto Nullius in verba ("take nobody's word for it') as a way to help students approach historical/critical thinking. I think this is a great way to encourage students to approach critical thinking without feeding into a complete erosion of truth. By encouraging them to ask questions, seek motivation of a source creator (as in the example you gave), and consider context, it's less about eroding the truth and more about uncovering the truth of the creator (ie. positionality or perspective).

I also think Crissy's (How do we know what we know? video) idea of introducing the professions that uncover and interpret sources of the past, the training they have, etc. helps students establish a process of the questions they ask and the research they perform to decide who they might trust.

As a side note, Lynn Hunt (History: Why it Matters) and Sarah Maza (Thinking About History) both do a great job of examining whether or not objectivity in history is even possible from the perspective of professional historians. Hunt's is a particularly quick read and very thought provoking.