I agree that a good researcher, biographer, historian,
will seek to go to
the most primary version that can. However for example, I have access to
hundreds of newspapers, the actual images of the actual columns from the time they
appeared. Most people do not.
Sure they do. You just have to go down to the local library. For the
most part, we're talking about academics/students so they can just go
to the Uni library which will have plenty of old newspapers.
Now let's say I state "Henry Fonda still
maintained relationship with his
ex-wife Margaret Sullavan as they were seen eating lunch together months after
the divorce" and I cite my source as the "Fresno Examiner", 4 Apr 1934.
Now someone could come along to my page, think that's interesting and cut
and paste it directly into Wikipedia, obviously citing the newspaper but
forgetting the courtesy of citing my work as the secondary citation. They did not
actually read the newspaper, they are leaching off my work to present some
interesting trivia to the world without even an acknowledgement.
That's backwards from what we're talking about. We're talking about
Wikipedia being the intermediate source for an academic paper, not an
academic paper being the intermediate source for Wikipedia.
Regardless, it's a good example of why you shouldn't trust Wikipedia
articles without verifying the source.
I try not to do that with my own sources, where I
can't actually get a copy
of the underlying source, and I wish others would make an effort to learn
secondary citation. Aside from that it's sometimes rather important to know
that a bit of data has been selected and filtered through an intermediary,
sometimes that knowledge alone colors the reading.
You should always cite the source you used, that's just common sense.
I can't see how anyone could argue that it's appropriate to cite
something you haven't looked at. Whether you should include that
source's source as well probably depends on the circumstances.