&gt;interactions crucially involve this notion.
&gt; &gt;
&gt; &gt;There are really two distinct issues here that I think 
&gt; you're conflating.
&gt; &gt;One issue is about the concepts that we admit into our 
&gt; ontology, and the
&gt; &gt;other is how we cash out these concepts and/or map them to 
&gt; other conceptual
&gt; &gt;schemes.  The merged ontology locates physical objects 
&gt; towards the top of
&gt; &gt;the hierarchy, but, as much as possible, it leaves open the 
&gt; question of how
&gt; &