Methodology Question: How to deal with others having written about similar topic? Basically, I am wondering how one is to deal with other scholars that have written about a similar topic or have covered similar/the same phenomenon (my field are the social sciences/humanities). What I will obviously do at the beginning of a chapter is to discuss the literature that has previously covered the events I wish to write about and explain how I will discuss/interpret these events differently in the article/chapter. But I am wondering whether in the unfolding of my argument that follows, I have to cite these works again for every minor point that others might have made about this topic? 

I guess it is difficult to give an example of such minor points, but if I discuss the same phenomenon or historical events that others have covered before, I am bound to make certain minor obvious points that others have made before, even though my overall argument/interpretation is different. The same goes for such minor obvious points that are made in the literature that is only distantly related (thus not necessarily appearing in my literature review).

The Turabian says the following:


  "7.9.3 Usually Cite a Source for Ideas Not Your Own. This rule is more
  complicated than it seems, because most of our own ideas are based on
  or derived from identifiable sources somewhere in history. Readers
  don't expect you to findevery distant source for every familiar idea,
  but they do expect you to cite the source for an idea when (1) the
  idea is associated with a specific person and (2) it's new enough not
  to be part of a field's common knowledge."


However, there is of course a large grey area to this. I would not say that the minor points I mean are in any way tied to a specific person, but whether that would mean I do not have to provide a footnote every time there is even a slight parallel point that I make. I understand that I could still simply always provide a footnote in such cases, but in practice that looks rather silly and it does not seem to be the case that other scholars in my field provide such citations for such minor points.

Thanks for your help.
There are a number of issues here, including the purpose of your writing and who you see as the audience. 

Don't however, lose sight of the fact that copyright applies to words (etc.) but not to ideas and concepts. History is full of examples of people coming to the same (or quite different) conclusions independently based on the same evidence - especially when that evidence is common knowledge. 

If you are writing for (potential) scholars it is probably better to give a lot of citations so that others can follow up and expand their knowledge of the field. I would prefer end-notes to foot-notes, however, as they are less disruptive of the page flow. 

If you are writing for popular consumption (a la Carl Sagan) you don't need to reference everything and your description of an introduction seems about right. You could, when writing, also have an appendix in which you point to the work of others who have discussed similar themes whether they come to similar conclusions or not. 

However, if you have to err, it is probably better to err (a bit or a lot) on the side of referencing related work that you know about. The fact that you know about it means that it may have had an effect on your own thinking and you should honor that in general. 

I think that when you are coming to different conclusions than others it might be especially useful to you to cite the work of others. Again, this is more important in scientific/professional writing than in the popular press. If nothing else this gives you the aura of fairness and leaves no one with a misconception that you were trying to mislead them. 

So, what is required to say and what is useful to say may not be quite the same.