Little can be done with a proposition that cannot be shown as true or false, and so busy readers can feel justified in moving on to the next book when offered one. Once we have a better idea of what the writer is saying, we can analyze the evidence to see if the proposition is true. This second level is where things get more complex. Evidence is not only a series of facts, it is also a method, called inference, of organizing ideas. To read a business book well, one must determine which type of inference the author is using.
Deductive inference starts from an assumption.
Scholarly economists, for example, deduce propositions from basic assumptions about human nature using mathematical logic. Anyone can make a deduction. It is up to you to assess whether the deduction makes sense. Peer-reviewed journals, the home of scholarly economists, typically screen out egregious instances where the answer to the second question is no. Unfortunately, very few business books are written in this paradigm, mostly because the kind of writing associated with peer-reviewed journals is not accessible to the general business reader.