Engage & involve
I'd like somebody to explain me the difference between these words.
May be I'm wrong but it seems to me that in some certain situations both of them mean
to participate in some activities, to take a part.
I'd like to understand if they are interchangeable in the following sentences
1. I'm not going to engage in hypotheticals here.
Is it possible to say 'I'm not going to be involved' in hypotheticals here ?
2. I'm sorry, myself and Morris were just engaged in quite a serious discussion about books and such.
Would it be correct to say
I'm sorry, myself and Morris were just involved in quite a serious discussion about books and such.
Of course it would be great to get any other hints or advices about using these words.
Thanks beforehand.