A colleague recently pointed out that it is crucial to make a distinction between mechanism and agency in discussions about the relationship between science and theology.
This is related to the issue of levels of explanation.
Science prescribes mechanisms but cannot answer questions about agency.
Theology can answer questions about agency.
Let me give a few concrete examples.
Why is the kettle boiling?
Mechanism: Because the stove heats the water to above the boiling point of 100 degrees centigrade.
Agency: I put the kettle on the stove because I wanted to make a cup of tea for my wife.
Why is the car moving?
Mechanism: The heat of combustion of the fuel drives the pistons in the engine.
Agency: I am driving it to visit my friend.
Why did galaxies form?
Mechanism: Gravitational attraction between clumps of gas and matter.
Possible agency: God wanted to make an amazing universe that would be a testament to His majesty.
Why is the universe expanding?
Mechanism: Einstein's theory of gravity requires the expansion following the Big Bang.
Possible agency: God prescribed laws for His Creation.
Where do different biological species come from?
Possible agency: God prescribed natural laws that would produce such species.