Dear Eden:

Well, you do not say what you are talking about specifically. I presume you are talking about DNA ligation (DNA ligase). There are other types of ligation.

I am not really familiar with DNA ligation, but I think this is what is popularly called Gene-Splitting. It is a procedure in microbiology to link together strands of DNA. 

This has promises, I would imagine, in Gene repair; that is, to repair damaged genes, or to perhaps correct negative traits, such as cystic fibrosis (which in my genetic history). I may be wrong about this; as I said, I really do not know much about DNA ligase. But, if disease traits in genes can be corrected, this would certainly be a moral good.

On the dark side, if this technology were used to perform genetic engineering on humans, that is, to create certain attributes and traits in the human person (so much like ordering from a catalog), or to "advance" human evolution into a super-human, and the like, this would be a moral evil. 

I hope this gives you some answer. But since I really do not know what I am talking about concerning DNA manipulation, I hope I got this right at least in essence.

God Bless,
Bro. Ignatius Mary