That fact becomes self evident if you take a look at the relation between this theme and those leading research on it.

A common theme underlies both perspectives.

His remark has nothing to do with the subject.

Have you decided on the subject of your thesis?

We will debate this subject at the meeting.

This theme should be treated in more detail.

It has been shown in most studies on this subject that intervention of the legislature had adverse effects.

Have you decided the subject of your thesis?

I've kept a blog before. I didn't really have a set theme; I just blogged about whatever happened that day.

I'm currently looking for a topic for my thesis.

What kind of theme are you interested in?

Have you decided on your dissertation topic?

That was the subject of my thesis.

"What was the name of that space theme park in Kyushu?" "Oh, you mean Space World." "Yeah, what happened to it?" "It went out of business a few years ago."

We discussed a wide range of topics.