When you can't go to the original sources

For better or worse, I am the product of a Reed College education. And Reed consistently urges its students to refer to original sources. Rather than read a textbook that talks about Plato, Reed would prefer that its students read Plato.

But what if the original sources changed?

This could very easily happen. As a Christian, I constantly encounter people who wonder about the "real" words of Jesus, before the editors supposedly changed all of them. Yet these same people accept the words of Plato as...um, gospel - despite the fact that half of Plato's Dialogues are derived from a manuscript from 895 AD, over one thousand years after Plato existed. If Plato's disciples didn't invent him, of course.

There are modern, secular examples of this. Just last month Louis Gray noted that Zillow changed its home pricing metrics and wiped out all of its old data. If you rely on Zillow's data, your home value may have increased or decreased significantly in a single day - not that Zillow displays any record of the old price.

Which is why I believe that all modifications to original data should be disclosed.