1.
You use ~ to emphasize that the thing you are mentioning is the most important feature or that it is the only thing which should be considered.
It is a racing machine, designed ~ for speed...
The government said the moves were ~ defensive.
ADV: ADV with cl/group emphasis
2.
You use ~ and simply to emphasize that the thing you are mentioning is the only thing involved.
If Arthur was attracted here by the prospects of therapy, John came down ~ and simply to make money...
PHRASE: PHR with cl emphasis