I’ve been reading one article and I want to include an idea that the author of this article cited from another source. Who should I cite as a reference- the current author for this article I have been reading, or the original source that the author cites?
In most cases, you should look for the original source. Here’s why...
Why you should cite the original source
Imagine you cite the more recent article, paraphrasing what they say and changing the idea very slightly. Now imagine your work gets published and in a few years somebody else reads your work and they pick up on this idea, paraphrasing you and changing it slightly. Now the original nuance of the idea might be lost and it’s harder to find the original source and check where the idea came from.
This happens all the time in the academic literature. In the worst cases, a secondary source becomes much more popular than the original and everybody cites them when talking about a particular idea. This might be OK, but if they misinterpreted or misrepresented the original idea, then there’s a problem as everyone else is building on a cracked foundation.
Another problem you might find is that when you look for the original source it isn’t available. I often found, when trying to track down original sources, that they were conference proceedings (many of which were not available online) or super-obscure journals. If it isn’t published in a proper journal, then it’s probably better to just not include that point.
Or, of course, the original source might not be very good work (just because it’s published doesn’t mean it’s good). Never cite an idea just because you want it to be true. If the research behind it is weak, either acknowledge this as a gap or leave the idea out completely.
So you should check the original source and find out where the idea came from, especially if this idea is an essential component of your work.
But let’s assume there is good research behind the idea.
Now it might be that the source you’re reading now describes the idea much more clearly than the original. In this case you could cite both, acknowledging where the idea came from and then following the logic of the later paper. For example;
In 1986 Smith proposed a radical new theory to explain X (ref). As Jones later explained (ref), this theory was based upon...
Of course, tracing original sources is extra work. As always when citing sources, though, you need to decide whether the idea is relevant and important to your work and worth the effort. One of the most common problems I see in PhD students’ writing is the random inclusion of ideas and references to show the reader how much they’ve read. This is not what the examiner is looking for. Focus on the best, most most relevant sources and exclude the rest!