Meta Ethics is the term used to describe the branch of philosophy concerned with the way Ethical language itself is used. Before a topic can be discussed, technical words need to be defined to ensure accurate communication. If two people have two separate definitions of a word relevant to the discussion of the topic, then they are effectively conversing in two different languages, semantically distant albeit acoustically the same, rendering the conversation meaningless and thus effectively pointless.
Meta-ethics seeks to define the words used in ethical debate, with the above attitude that fruitful debate about the morality of an issue must be preceded by a thorough investigation into the definition of morality. Without the use of meta-ethics, understanding of ethical theory would be somewhat “fluffy,” that is to say without solid substance. It would be all well and good to understand that something is good, but goodness can be interpreted in numerous ways.
If I suggest that fruit is good, am I saying that I personally feel that fruit is good, in which case I am stating that the goodness of the fruit is relative to the consumer; or am I suggesting that the fruit is good in an absolute manner, that whatever the circumstances are of the consumer, or indeed the item of fruit concerned, the fruit is by very nature of its status of fruit good based on an independent, external value system.
Am I recommending that people should all go out and stock up on fruit, or am I only expressing my own personal enjoyment in fruit. However this is slightly more complicated than it may seem, and it is the complexity of meta-ethics that is also its downfall. Where this becomes complicated is with the fact that people talk about goodness, not simply in moral terms, but also in an amoral sense.
The goodness expressed in a non-moral sense, i. e. the aesthetic goodness of a painting, is not the same as the goodness expressed in a moral sense, i.e. the goodness of marriage. When I express my opinions over the goodness of a moral issue I could be expressing my core values in life, in which case for you to disagree would be an attack on my most essential values, what morally defines who I am. However if you were to disagree with me on an aesthetic issue, would I react in the same way? I suppose it depends on the importance I put on the idea of morality. What I mean when I say something is good, may well depend on the context of the issue at hand.
Without this definition of goodness, understanding of ethical theory would be completely dependant on the rare chance that the person I am discussing ethics with is so in tune with me, that he has the same definition of goodness as myself in a particular context. I hesitate to add that somebody who is so in tune with me, would probably have the same ethical opinions as me, as we obviously have a similar background to have an identical language system, making a “balanced,” ethical debate with two diverse views, quite difficult.