Is "は" really a "topic marker"?


I hope this doesn't count as one of the は/が difference duplicates (that isn't
what I'm asking), but I'm slightly confused about how to think of the は
particle. I've heard it called the "topic marker", but I've also read a
separate explanation about it being an "emphasizer" that connects
subject/predicate: [An historical grammar of
Japanese](http://www.archive.org/stream/historicalgramma00sansuoft#page/258/mode/2up).

Is this a better way to think of it? Which is closer to how it's used in the
colloquial/modern grammar?




> Is “は” really a “topic marker”?

Yes, it is.  
_A Japanese subject_ (主語{しゅご}) _is not necessarily the action maker_ , but is
actually purely 'subject'; it's always the topic/theme to us, native Japanese
speakers.

_Cf:_ An English subject is also not an action maker when the verb is a link
verb like _is_ or _seem_. However, the grammar term 'subject' seems to have
been defined as the action maker of the verb.

は is considered as 係助詞{かかりじょし}; it determines the ending (main) verb (phrase).
Some linguists consider it as 副助詞{ふくじょし} from the perspective of its
complementing (adverbial function to) the verb.  
(が is considered as 格助詞{かくじょし}, the case marker, and is good for being used in
modifying clauses. が also makes a sentence without any は, but は is the one to
talk about _general ideas_ ; が introduces a happening, and sometimes it
doesn't make any difference whichever is used.)

> I've heard it called the "topic marker", but I've also read a separate
> explanation about it being an "emphasizer" that connects subject/predicate:

The particle は has a sense of _comparing_ , while が has a sense of exclusion,
but emphasis actually can be done by any particle.

I think, as a native speaker, I should confirm that the example sentences in
Japanese brought up by @Structure are all perfectly natural.

