1. Legal Positivism Two Central Theses Broad and Narrow Positivism
Soft and Hard Positivism
What is Positive Law?
The Command Theory
The Social Convention Theory

2. Two Central Theses
Issues of legal validity must be strictly separated from questions of morality. What the law ought to be has nothing to do with what the law actually is.
There are irreducible facts about political society that can only be expressed in the vocabulary of the law. The study of the law is autonomous.

3. Broad and narrow positivism
Broad positivism (= moral/legal conventionalism). There is only the positive law: there are no objective, universal facts about morality, about what the law ought to be like. [Hans Kelsen]
Narrow (legal) positivism: in addition to the positive law, objective moral facts may exist. Legal validity is independent of moral justifiability.

4. Two kinds of (narrow) legal positivism
Utilitarian positivism: there are no natural human rights, nothing like a natural law. The only moral standard is one of the desirability of the consequences of the law. [Bentham]
Non-utilitarian narrow positivism. There is something like natural law (universal human rights, universal moral principles).

5. Common ground
A positive law is binding even if it is supremely immoral.
No principle of morality is legally binding until it has been enacted into positive law.
That a statute is legally binding does not settle the moral question of whether we ought (morally speaking) to obey or disobey the law.

6. Soft vs. Hard Positivism
Soft positivism: there is no necessary connection between the content of law and the truths of morality.
Hard positivism: there is, of necessity, no connection between the content of law and the truths of morality.

7. Soft Positivism Defended by H. L. A. Hart.
Society may, if it chooses, incorporate the principles of morality into the law. E.g., prohibitions of “cruel” punishment, requiring “just” compensation.
However, this is merely an option: no moral principle is legally binding unless it is incorporated into the law.

8. Hard Positivism Defended by Joseph Raz (Oxford).
It is impossible for the law to incorporate moral ideas or principles.
Apparent cases of this are merely decorative, without legal force.
Why? The purpose of the law is to enable society to avoid and resolve disputes. Applications of moral truths are always disputable.

9. What is positive law? The Command Theory (Bentham, Austin)
The Social Convention Theory (Kelsen, Hart)

10. Bentham/Austin Command Theory
X is the superior of Y if and only if Y is in the habit of obeying X, and not vice versa.

11. The Sovereign
A collection S of human beings constitutes an independent political society just in case there is one member X (or some compact body X of members) of S that is the superior of all of the other members of S, and there is no human being Y outside of S who is the superior of X. In such a case, X is called the sovereign of society S.

12. Commands
A command from X to Y is the expression, in words or actions, of the desire of X that Y act in a certain way, backed up by a stated or implied threat to impose some penalty on Y if Y does not comply.

13. General Commands
A general command is a command that is issued to an entire class of individuals and that is intended to stand for an indefinite period, until revoked by its issuer.

14. Positive Law
A positive law is a general command issued by the sovereign of an independent political society to some or all the members of that society.

15. Some problems with the command theory.
The theory applies clearly to an absolute monarchy, but is much less clear when applied to a society where some group is the sovereign.
What exactly does it mean to obey a group?
Can a group issue commands (in Austin's sense) -- can a group share a single desire?

16. More problems
H. L. A. Hart argues that the command theory cannot distinguish between a legitimate government and an armed robber ("give me your money or else"). The "Gun Man" objection.
Parliamentary or constitutional law, laws governing the actions of the sovereign, do not count as law at all.