Study materials
These three sentences describe one situation, and what separates them is not the strength of certainty.
The system may be unstable.
The system is reportedly unstable.
We argue that the system is unstable.
At this level modality separates into three independent scales. They are easy to confuse, because all three are expressed by similar words.
Three separate scales
What is usually lumped together as modality is in fact three independent dimensions.
| Dimension | Question | Devices |
|---|---|---|
| certainty | how likely is it | must, may, is likely to |
| source | how do I know | apparently, reportedly, evidently |
| accountability | who is claiming this | we argue, it is argued, Smith argues |
The system may be unstable.
The system is reportedly unstable.
We argue that the system is unstable.
The dimensions are independent. You can be very sure of somebody else's claim and very unsure of your own observation.
The source of knowledge
English has no dedicated evidential forms as some languages do, but it has a set of words that does the same job.
Apparently, the meeting was cancelled.
Evidently, the meeting was cancelled.
Clearly, the meeting was cancelled.
Three words that dictionaries gloss almost identically report different origins of knowledge. Confusing them damages academic prose quietly but systematically.
Where it breaks down
The first failure: a probability estimate stands where a source is wanted.
The results may be inaccurate.
The second: clearly is used where nothing is clear to the reader.
Clearly, the method is superior.
The third: two dimensions have merged into one word.
It seems the data are incomplete.
All three are caught by three questions. How sure am I? How do I know? And who is answerable for it?
Try it right now
Take one claim from your field and write it in English three times: with a probability estimate, with a named source, and with named accountability.
Then check each: have you merged two dimensions into a single word?