(Excerpted from Elizabeth Shown Mills, Evidence Explained: Citing History Sources from Artifacts to Cyberspace, 3d ed. rev. (Baltimore: Genealogical Publishing Co., 2017), pp. 52, 180, §2.21, 4.6.)
In the following excerpt from her acclaimed book, Evidence Explained: Citing History Sources from Artifacts to Cyberspace. 3rd Edition Revised, Elizabeth Shown Mills explains why researchers should avoid citing a second source that is quoted by the source we are currently evaluating. More sage counsel to bear in mind as we delve deeper into our family history!
“We do not cite sources we have not used. “Borrowing” sources from other writers is both unethical and risky. When we use the work of others, we cite what we actually used. When other authors identify their source for a detail that is relevant to us, we should add to our note a statement such as the author cites “Register 3, page 235, St. Peter’s Parish, Wilmington.”
Credit should always be given where it is due. By the same token, we would not wish to assume the blame for an error another writer made in using a record we have not seen. If the source we consulted cites an original record, we should then examine the original to verify the accuracy of the prior writer’s assertions. Having consulted the original, we are entitled to cite the original as our own reference.
If the other author has given us special insight into the use or interpretation of that original, we should credit the prior author for the insight. If the original material is something we might not have found on our own, we might also credit the earlier author for pointing us to it. Conversely, if the earlier author misrepresents facts from the original, then our citation might need to note that error and add an appropriate but tactful discussion.
Commercial firms that provide historical content should identify their own source. Most do attempt it in some fashion. You may need to adapt it. When using online content, your reference note should include relevant details for both the website and the source of its data. To separate those two layers of the citation, you would use a semicolon. In such cases, the first part of your citation should always be to the source you actually use. The source of your source is then cited secondarily, until and unless you personally consult it.”