Is well known Hume's argument in A treatise of Human Nature that we can't derive normative judgments from descriptive statements. Recently one of my teachers said that Putnam proved Hume wrong showing that ethical judgments are in fact connected with cognitive judgements and therefore it is possible to have solid grounds for some ethical claims.

Not knowing much about Putnam I ask here, did Putnam actually show that?, what is the general opinion in the philosophical community about Putnam's works on ethics?