In need of a English Lesson

Hi Ranchers !
Needed a little help with English grammar usage.
Thought I'd ask the people whose mother tongue is Java... !
Pls. indicate the correct usage ...
"Culture and Heritage are the foundation of a society"
OR
"Culture and Heritage is the foundation of a society"
thanks a ton
- Himanshu

Culture and Heritage are the foundation of a society
The sentance has a compound subject, which is treated the same as if it were plural subject. The verb 'to be' appears as 'is' with singular subjects and 'are' with plural subjects.

Although if the subject is plural, you would expect to see "foundations" rather than "foundation". Perhaps the author is treating them as a single idea...

I'd say
Culture and heritage comprise the foundation...
if I were emphasizing them together, as a single foundation that includes the two elements, which I think is the intent.
If I meant them separately, I'd say
Culture and heritage are the foundations ...
I'd use this if the context were that society consists of several parts, with culture as the foundation of some parts, and heritage as the foundation of other parts.
I think that what leads me to this the common association of the term foundation with the foundation of a building. I think of a foundation of something as a single unit, perhaps comprised of several parts. The meaning of foundation may broader, but I think this association is like to be strong in the mind of the reader, and fits the context. This leads to the use of "comprise" in this case.
If I saw
Culture and heritage is the foundation...
I'd be briefly distracted, but I'd assume the author meant "comprise".

Hmmm, I wonder why William Safire hasn't contributed to this thread