Meta ethics is the study of the issues that underpin all ethical discussions. What is the nature of ethical language? What do the words "good", "bad", "right" or "wrong" really mean? Are human beings free and responsible? What is a human being? Who counts as a person and who does not? What is the difference between a human being and any other animal? Is moral status dependent on DNA, on rationality, socialisation – or something else? All of these are matters of meta ethics.
Ethical language is beset by many of the same problems as religious language. This topic is given fuller treatment in the Philosophy section of this site under Language. Statements including claims about goodness, badness, rightness and wrongness are basically unverifiable. There is no empirical test to back up such claims, no probe whose readings will confirm that "murder is wrong", for example.
Plato and Aristotle
From the earliest times philosophers have sought to define goodness to support claims concerning it. Plato offered a metaphysical definition of goodness as a reflection of a mysterious "the form of the good", which exists beyond time and space in the realm of ideas and which we recognise in some things and actions but not in others, by bringing the assessment of goodness firmly within the realm of human experience. Aristotle reacted against the ambiguity of this. For him, goodness came in the degree to which something fulfils its nature. Aristotle saw that our understanding of the nature or form of things starts with our experience of them. For example, we might see a lot of trees, learn about them and become knowledgeable about what they should be like, and this enables us to judge some trees as better than others in terms of how well an individual specimen measures up to what a tree could and should be in our experience. Judgement is a rational process but it is based on categories which are derived from direct experience - Aristotle's approach does not rely on human beings having any mysterious understanding of metaphysical truths as Plato's did.
For Aristotle, reason dictates that a thing's nature is made up of four causes - its material, efficient, formal and final causes.
a. Material causes are the basic ingredients that make it up. b. Efficient causes are the agents and accidents that bring it into being. c. A thing's formal cause is what makes it what it is, its recipe or nature. d. A thing's final cause is its purpose, what it aims towards.
Take an oak tree. Material causes would include carbon, oxygen etc. Efficient causes would include acorn, earth, sun and rain. The formal cause would be the oak's DNA (as opposed to that of elm, ash or wombat) and the final cause would be growing, reproducing and so on.
Aristotle argued that a good object fulfils its formal cause – i.e. it is a good example of what it is - and so achieves its final cause to the best degree. Basically, for Aristotle, goodness lies in flourishing. A "good" oak tree grows very tall, produces many acorns from which new saplings grow, and so on. Conversely an "evil" oak tree ("evil" naturally, rather than morally, because the oak is a non-free and thus non-moral being) would be small, infertile and generally functioning poorly.
This applies to human beings as well as to all other things. A good human being is fully human, continues to live, grow, reproduce and otherwise flourish. An evil human being, either naturally or morally, fails to fulfil their humanity and falls short by living a short, poor, barren and insignificant life. This is the basis of Aristotelian natural law and has been used as the foundation of naturalistic ethics from Aquinas to Grisez and Finnis.
Applying Aristotle's definition to humans
Using Aristotle's definition of goodness would yield some grounds for claiming that something was good or that something else was better than it. Yet the criteria for making these judgements are arguably subjective. Can we really and conclusively define human nature? In the eighteenth century Hutcheson, Bentham and others looked for a simpler basis for making claims about good, bad, right and wrong. Building on Locke, Hume had argued that these judgements are simply expressions of opinion or emotion, and so had opened up the road towards radical relativism, postmodernism and the dominant emotivism of the twentieth century.