This question goes to the basic heart of why research is conducted in the manner it is. The function of the in- text citation/ internal citation is to give credit to another's work where it is due. When work is properly cited, it shows that there is a respect for someone else's ideas. In being able to document the origin of an idea through citation and page number, the author shows themselves as part of a dialogue. The writing that happens in the academic/ scientific world is one in which a free exchange of ideas is essential. The only way this is possible is if there is proper attribution of ideas to others. Citing a work shows that the individual is willing to partake in a discussion and exchange of ideas that started before them and will continue after them.
The academic/ scientific setting is a domain where these ideas are essential to intellectual discourse. If there is no citation, then a dangerous door opens in which intellectual property can be usurped and stolen. The entire premise of the intellectual dialogue and free exchange of ideas is threatened where there is not a healthy respect for where ideas originated and who developed them: "Citation is important because it is the basis of academics, that is, the pursuit of knowledge. In the academic endeavor, individuals look at evidence and reason about that evidence in their own individual ways." The direct function of the in- text citation is to show where these ideas originate and how they merge into a writer's thought process. The attribution of ideas and ownership of ideas is what allows the intellectual dialogue to emerge. Thinkers have examined other ideas that preceded them and used them in forming their own ideas. Since intellectual discourse has been around, the need to cite where these ideas came from has been essential in furthering the dialogue.
Citation demonstrates a healthy respect for this dynamic. There is a shame associated with stealing another's ideas or failing to cite them accordingly. It is a line that the academy has emphasized should not be crossed. Esteemed individuals such as Doris Kearns Goodwin have paid dearly for not citing work properly. Citation plays a vital role in establishing and sustaining the credibility of the writer. Since the writer operates in the realm of ideas, when there is a practice of improper citation of others' work or if someone seeks to pass off these ideas as their own, their credibility is damaged. It represents a violation of trust that the academy argues makes its own pursuit of intellectual discourse fundamentally unique. Unlike other domains, the value of an idea and the ability to exchange ideas in dialogue are intrinsic goods. Such intrinsic notions can only be preserved when there is a respect for ownership and citation reflects this. Doris Kearns Goodwin's case demonstrates how a writer's credibility is threatened when citation is not properly followed. It shows us that a lifetime of work can be threatened when citation rules and expectations are not appreciated. Credibility is a type of public trust, one that is damaged when citation is absent or when plagiarism is present. It is with this in mind that universities respond intensely to academic dishonesty or citation errors. The need to establish credibility through this trust is why citation is so important for so many.