Comment by gyomu

If your definition of machine is "purely physical object behaving according to rules"[0], then one could argue that everything in the universe is a machine, which is not a very useful definition.

[0] where I assume you mean rules = "laws of physics", because if we were to choose the more conventional definition of rule = "an accepted principle or instruction that states the way things are or should be done", then your own definition doesn't apply to cells or other biological entities