It is worth noting that the movie "Amistad" (which I remember fondly) is set in the early nineteenth century, and the scene in question is one of formal and sarcastic speech. This means that the usage is rather different than it would be in a more modern setting.
By "measure of grace" the speaker here refers to elegance. But in that time "grace" also had routinely a Christian religious connotation, and that usage also colors the speech here. The speaker is saying that mere technical knowledge is pointless without more moral qualities -- I would need to rewatch the movie for fuller context to be more precise. I suspect the speaker is also implying that Joadson is not in fact as knowledgeable and learned as he purports to be, but I would need to check the context to be sure of that.
This is a case of using particularly polite forms to imply a negative message. This was a style much more common when the film is set than it is now.