Plural / Singular verb in this sentence?

Recently an editor just changed the plural verbs in my essay to singular ones, but I don't understand why he did so. Please see below:

(Original sentence) After rising to power through multiple revolutions, the Chinese Communist Party holds a subversive notion and ideology that not only aspire to break the old world, but also aim to build a new one.

(revised sentence) After rising to power through multiple revolutions, the Chinese Communist Party holds a subversive notion and ideology that not only aspires to break the old world, but also aims to build a new one.

In my understanding, there are two nouns in "a subversive notion and ideology", and that should be followed by a plural verb?

Solution 1:

The key is in the use of the indefinite article.

To paraphrase:

The CPP holds a ^{subversive notion and ideology} that aspires . . .

I have put the subject in superscript in order to set it off from the rest of the text. Especially because of the a, the syntax treats the phrase as a compound single subject.

It is the same idea as:

This ^{fish and chips}is delicious.

Although there are actually two separate things joined together, they are thought of, and treated as, a singular item.

In order for the syntax to show that there are multiple things being used as individual subjects, you would need to remove the indefinite article and pluralize the subjects:

The CPP holds subversive notions and ideologies that aspire . . .

Alternatively, it's possible to use a phrasing similar to what follows—but it would be somewhat awkward:

The CPP holds a subversive notion as well as a subversive ideology that both aspire . . .

Solution 2:

Yes. tchrist and Minty are right I think. But are both the notion and the ideology subversive? It isn't quite clear. And can a notion itself aspire to do something? Perhaps an ideology can, but I'm not sure. I would leave notion out, and say something like

"The CCP's subversive ideologies suggest that it aspires not only to break the old world but also to build a new one."