Are you following me? Tips for Authors: Avoiding a Non-Sequitur

‘Non-sequitur’—does anyone even know the meaning of this Latin phrase anymore? Roughly translated it means ‘does not follow.’ In writing, it means that one sentence, one idea, does not follow logically from the previous one—sort of like that T-shirt for attention deficit disorder (“They say I have ADD. They just don’t understand…. Oh, look! There’s a chicken!”). In writing this happens for two reasons. The first, and probably most common, is that you, the author, have been so engaged in the writing that your brain just fills in the blank between ideas. So, in your mind it does follow. The second reason is that you actually do not know how you got from one idea to the next, just that they both have to be included. In either case, the relationship between the ideas in the two sentences or two paragraphs is not explicit, and in writing, it must be explicit for the reader. In order to do that, you need to have several things operating simultaneously—a detailed sense of the overall logical structure of the whole document, a detailed sense of the logical structure of the paragraph, and identification of words or phrases that can link one sentence to another (or one paragraph to another). I have already discussed overall logical structure of a document, if we are discussing a scientific manuscript, so I will not go through that here. However, I have not broken down paragraphs or discussed how to link sentences (and paragraphs). That is what I will address here. I am sure there are English texts out there that do the same thing, but I am going to emphasize what a researcher needs to consider.

It’s a toss up whether to discuss paragraphs or linking phrases separately, but I am opting for focusing on paragraphs, in part because if you get the paragraph organized right, you will probably not have to worry about sentences not linking properly. For full disclosure, let me say I am extremely biased when it comes to paragraphs! Look up paragraph structure online, and what I am saying will be right in line, with a little wiggle room for scientists. The basic structure of paragraphs is the topic sentence, supporting sentences and concluding sentence—roughly 5 sentences, with a range of 3-7 sentences depending up the purpose of the paragraph. Keeping it this length feeds into the reader’s expectations, and using the reader’s expectations makes your writing more appealing and acceptable. For scientists, when the first reader is likely to a reviewer judging their work, tapping into these expectations goes a long way in getting a favorable review. So, let’s go through the logical structure of a paragraph, but I will include comments that will help in link paragraphs together as well, while covering linking phrases at the same time.

The Topic Sentence: As you will find it defined in your basic middle school English text, this tells the reader what the entire paragraph is about. Note that I included and italicized the word ‘entire’. Every sentence that follows will either refer to the topic explicitly, using the same phraseology in the topic sentence, or will use the topic sentence as the logical starting point. It sets up the reader’s expectation of what is to follow. If this is the very first paragraph of the document, then the paragraph will set up the words and phrases that a reader will expect to see throughout the document. Topics sentences are logically critical. If you list all the topic sentences in a document, they would literally be the outline of the logical structure of the document, demonstrating the flow from one idea to the next.

Supporting sentences: These explain in more detail the topic sentence, or they give the logical inferences from the topic sentence, depending upon the purpose of the paragraph. For example, if the topic sentence is “Atrial fibrillation has proven to be difficult to study at the cellular level,” then the next 2-4 sentences might explain why it has been difficult. If the topic sentence is “Mitochondrial-controlled apoptosis has become more accessible to study because of the development of new markers for apoptotic pathways,” then the next 2-4 sentences might outline the logical inferences for research derived from the development. In both cases, the next sentence would build upon the topic sentence using a word or phrase from the topic sentence. For example, in the first case, the next sentence might read, “Isolation of viable atrial cells, a necessary first step to studying atrial fibrillation at the cellular level, has been unsuccessful despite many attempts.” In the second case, the next sentence might read, “The identification of Xyz and Abc as key components in apoptotic pathways permits a deeper understanding of the role of mPTP in mitochondrial apoptosis, since they have also been shown to control mPTP opening.” Note the use of the same words or phrases from the topic sentence in the second sentence (underlined). The repeated words and phrases keep the reader moving along with you. The next sentences would do the same, using words and phrases from the sentence preceding them, not necessarily verbatim, but similar like the word ‘unsuccessful’ points back to ‘difficult’.

Concluding Sentence: The last sentence of a paragraph may have two functions. It must sum up the point being made in the paragraph, but it might also set up the next paragraph. In many cases it restates the topic sentence and then the says something more about it. For example, in the first case the concluding sentence might read “The difficulties in studying atrial fibrillation have been reduced now that viable atrial cells can be isolated reliably,” (assuming that is where the paragraph went), but note the paraphrasing of the topic sentence into the subject of the concluding sentence and then making a conclusion about the subject based on the rest of the paragraph, it can also go on to explicitly set up the next paragraph, either by the addition of a clause or even another sentence. There is no rule that says the concluding sentence is the last sentence, just that there has to be one. For example, the paragraph could end with a set-up sentence, such as "However, these isolated cells have not been fully characterized electrophyiologically". This points the way to the next paragraph that will discuss the characterization of the isolated cells. Note that the paragraph could have ended with the concluding sentence, without any logical disruption, because the linking phrases were maintained.

If you keep your reader's point of view in mind while you write, some of the logical jumps you make naturally for yourself will not happen. It is hard, but by linking text from sentence to sentence and paragraph to paragraph, then your writing will flow and your readers will follow.