In the grammar book I am using, subjuncts are defined as playing a subordinate role in a sentence. One of these uses, as given in the book, is to express a point of view:
"Morally, he should resign."
On the following page the book gives this example for a disjunct:
"Frankly, John should never have done it."
Style disjuncts express the conditions under which the listener/reader is to interpret the sentence. My question is borne out of a confusion: how do I distinguish between these two examples? They seem very similar to me.