In order of importance, except for mathematics which I found impossible to place because it runs in the background connecting all our knowledge and paving the road to see things we never saw before.
Where did we come from ? Physics
Where are we going? Engineering
Why are we like this? Social sciences
Why do we like this? Arts
What medium to elegantly describe it all ? Mathematics
Forgot any fields ? they are probably not important.. put them in comments and I'll reconsider.