I definitely believe that assemblies have properties that cannot be seen or predicted from the properties of their constituents. Call them emergent properties or whatever.
This is one of the reasons I find it silly to have arbitrarily limited expectation of what is possible with "matter", or to divide existence into matter and spirit. I can't prove this dichotomy isn't real and true, but I haven't seen the need for it.
"Call them emergent properties " stresses the point you wish because the other view considers a complex or duality: put all the pieces together and you still don't have life because nothing new comes into existence when you do that--you need a governing principle which is immaterial and that principle would continue to exist after the dissolution of the constituent material parts.
But the distinction between life and non-life pertains to both views.
The advantage of a science is that it sufficiently dilineates a portion of the world we live in and analyzes those features that systematically cohere in it.
This makes it a safe zone: you can do ethics without becoming a mathematician, you can be a successful lawyer without ever touching a musical instrument. This also turns into a huge problem in academia, nobody realy has the need for a colleague outside of their own discipline. :(
No one is trying to "arbitrarily limit" matter to anything at all. As the basic constituent or "building block" of nature, conceivably matter could be anything at all in theory. Ours was but a mere attempt to describe things that have fallen within the jurisdiction of our own little limited "ken," as qualified by actual observations discerned from the perspective of our own little insufficient perch in Reality.
This sort of thing is otherwise known as "qualified evidence." Nobody asserts that the qualified evidence thus adduced is alone sufficient to explain the entire system of which it is a part.