But the distinctions between biology and organic chemistry are matters of definition, construct and convention.
So where, exactly, does complex chemistry end and simple life begin?
If we look around the natural world today, we can see examples of both, and some seemingly half one, half the other.
That complex organic chemistry can evolve naturally is observable, testable, confirmable and therefore indisputable.
That evolving natural organic chemistry will, under certain circumstances, "complexify" is also demonstrable.
Of course, how, exactly complex chemistry became simple life we don't yet fully know, but nothing discovered so far makes that impossible.
The complexity of just a single cell argues that there is no way it could evolve by chance. That is like arguing that the Mona Lisa was created when a tornado went through Michelangelo’s studio and splashed paint on a canvas.