(b) The first clause may be omitted and still leave a complete and intelligent sentence; if we were to omit the second clause, the sentence would cease to have any meaning.
These tests may be practically useful; but they are rough and by no means infallible. Let us see the reason for the distinction.
The name "Religio Laici" of itself tells us what thing is spoken about. It is the name of one thing, and only of one thing. The clause that follows informs us, indeed, of a fact concerning the poem; but the information is given purely as information, not in order to keep us from confounding this "Religio Laici" with some other "Religio Laici" that did not borrow its title. "Work of Dryden," however, is the name of a class, for Dryden wrote many works. Now the whole class is not here in question; it must be limited, narrowed, or restricted, to one part of it, namely Dryden's voluntary effusions; and it is thus limited, narrowed, or restricted, by the relative clause "which can be considered as a voluntary effusion."
Take another example, where the name in both cases is that of a class, and note the difference of meaning which results from different pointing:—"The houses in London which are badly built, ought to be pulled down." "The houses in London" expresses a class of objects; the relative clause limits the name to a smaller class, the badly built houses; and the meaning is, that houses of this smaller class ought to be pulled down. Now insert the comma:—"The houses in London, which are badly built, ought to be pulled down." The class is not narrowed; and the meaning is, that all houses in London, seeing they are badly built, ought to be pulled down.
The difference between the two kinds of relative clauses being understood, there will be no difficulty in applying the rule where an adjective clause is contracted. Compare the fourth example given under the rule with the following sentence:—"People not satisfied with their present condition, should strive to alter it." In this sentence "not satisfied" limits the general name "people"; the advice is given only to one section of the people: the dissatisfied as distinguished from the satisfied people.
So a single adjective may be used co-ordinately:
"What!" replied the Emperor, "you do not see it? It is my star, brilliant."
This is a case where a dash would be more expressive.
Note that the rule applies only where the adjunct immediately follows the substantive. If the adjunct is placed elsewhere, different considerations apply. See [Rule XIII.] (3).
Neither can any man marvel at the play of puppets, that goeth behind the curtain and adviseth well of the motion.