[yrdmb]

> The cell is a living organism because we have largely defined the cutoff for living organisms at the cell;

Isn't that because all living organisms are composed of one or more cells ( cell theory )? It isn't an arbitrary cutoff but rather a result of observation that the smallest thing we can confidently called a living organism is a cell and all organisms are composed of cells.

> it's much more interesting to consider if viruses are machines or not and that really is a hot-topic in the biology community.

They are not self-contained self-replicating machines. But are they machines nonetheless? I'd say they are non-self-replicating machines. But I guess it all depends on how you define machine. Just like how do you define life or living determines whether viruses are alive or not.