Cognitivism

Breakdown
The part of meta-ethics that says that ethical sentences express propositions (statements of truth, that cannot be disputed). Non-cognitivism is the opposite of this theory, that states that ethical statements do not express propositions, therefore moral knowledge is impossible. Cognitivism is a big subject, not as big as your mum, but potentially bigger than Kanye West's ego, on a bad day.

As it is so big, it encompasses ('includes' for everyone who doesn't like needlessly complicated words) moral realism - ethical statements express propositions about mind-independent facts of the world; moral subjectivism - ethical statements express propositions about people's attitudes or opinions; and error theory - ethical statements express propositions, but they are all false, whatever their nature. Bit of a strange one that last one.

Moral Realism
Moral Realism is one of the two main parts that comprise meta-ethics, and if we take the red pill and see how deep the rabbit hole goes, we find that Ethical Naturalism and Ethical Non-Naturalism comprise Moral Realism, and then Ethical Naturalism is comprised of Reductive naturalism, and Non-reductive Naturalism. So essentially, once you reach Reductive Ethical Naturalism you are reading half of the half of Ethical Naturalism, which is half of meta-ethics, which is also a part of ethics as a whole, and ethics is, of course, half of this course. So we're talking at least 6 layers of dream here, and considering it's a week the first level down, 6 months the second, and a year the third, we might be here a while.

Reductive Naturalism claims that:

 * 1) Ethical sentences express propositions.
 * 2) Some of these propositions are true.
 * 3) These propositions are made true by objective features of the world, independent of human opinion ("Sworn never to interfere, only to watch").
 * 4) The moral features of the world are reducible to some set of non-moral features

Non-Reductive Naturalism claims that:
An example of a reduction that Red/Nat believes in is goodness is ultimately just pleasure, according to Hedonism. Altruism is a separate example - we can do good things for other people, while egoism, another one, states all good we do, we do it ultimately for ourselves.
 * 1) Well it's the same really, just that (4) says 'are not reducible, but instead supervened by some set of non-moral features' while Reductive Naturalism says that moral features 'are reducible'. Not much point in writing out the whole thing again.

No other examples were really offered unfortunately. If you do think of any other examples of reductions, don't hesitate to call 999 and whisper into the phone "Orange is the new black. Literally, orange has completely replaced black, we no longer have any concept of black. Someone needs to know about this." And you will be contacted shortly.

Ethical Non-Naturalism
Ethical Non-Naturalism claims that:
 * 1) Again, it's the same as the list for Red/Nat, just that it claims that moral features of the world are 'not reducible'

Moore on this.
His Naturalistic Fallacy. That is all.