Installation vs. Object: Longevity?

I had a web dialogue with another artist about object based art verses space based art. Installations involve some arrangement of paintings/drawings/wall markings/projections and/or free standing or sculptural elements (or monitors) in a space, and presumably some idea of transitions between the two (plus, perhaps some extra conceptual trappings), and in some cases, a time or 4D element. Nowadays, some artists even hang a bunch of paintings and call it installation because installation has become a buzz word.

While I see installations as the natural result of integrating the various elements that make up perceptions of art work and effect its interpretation, I have my own current issues with a feeling of emptiness in a fair amount of installation art I see. That was not his concern, though. His focus was on which form would outlast us (the artist) in some way defining Art, arguing in favor of painted sculpture. His concern seemed to be that the installation art will lose it's integrity once the artist/space are gone and some other artist, curator, etc is interpreting whatever survives from the installation, whether that's an object or documentation. I can see something to the idea that the individual pieces comprising the installation do not necessarily stand alone -- it depends on the concept of the installation. Still, any object is appreciated differently depending on its context, and rare is the long-lasting object that is seen in its original context. To me, the form -- painting, sculpture, installation hardly seems to be the means for defining Art. Whatever lasts will be defined and redefined by others.

His group's website is www.sculpturepainted.com.