[burade]

It's a good point though. Who decides what "one reason to change" is? a 10-line method could easily have hundreds of reasons to change.

[TuringTest]

I think the point is that you wouldn't apply those hundreds of reasons all at once. But it your code is doing two things, you could end up having two reasons to change it at the same time.

[sorokod]

You the programmer do. Do you expect everything to be automated by successive application of precise rules?