Pneumatology ≠ pneumology

I have this strange subject that, regardless what your field of study is, you are required to take it. It's called Religion, meaning and world-view. It bores the pants off if you're not into that kind of thing. Some theologist saying this and then another theologist not agreeing because of God knows what kind of reason.
The text we're using is larded with words like creed, revelation and eschatological.
Anyway.
I was reading through this bit of text on a certain Mr Jürgen Moltmann. I got through a paragraph but it didn't really make any sense.

It says (roughly translated): "In the third volume the insights from previous works are completed by reflections on ecclesiology and pneumatology."

I could't quite work out why a theologian would be remotely interested in combining religious studies with pulmonary diseases. Could it have been because of the crucifiction Jesus had a hard time breathing with all that water in his lungs?

It didn't make sense. None at all. The penny dropped quite late after a bit of confusion.
And then it dawned on me: Pneumatology is not the same as pneumology...