Positive and Negative Liberty
One thing jurists and philosophers have often pondered is the differentiation between positive and negative liberty. To the untrained eye, freedom is freedom, and that is that. However, some freedoms are ours by right of law; others are ours by right of there being no law restricting it.
Positive freedom is basically freedom guaranteed to you by the law. Nobody can take it away from you; it is an absolute entitlement. The freedom of speech is one such example in many liberal democracies; the right to private property is another example found in most countries.
Negative freedom is freedom that is yours because no law has restricted your exercise of that liberty. There is no explicit law saying I have the right to celebrate my birthday every year — I exercise that liberty because there is no law saying I cannot exercise it (well, actually, not really; with each passing year my birthday becomes less and less of a deal, but it's just an example).
There has been significant debate on which form of liberty is superior — positive or negative liberty. It seems like an academic debate, but there are significant implications in the real world based on how we decide.
You might think that positive liberty is clearly better; it is after all, always good to have our rights and freedoms explicitly spelled out. The British recognised this and moved from their principle of an unwritten common law constitution towards something more explicit — one of Tony Blair's first moves as Prime Minister was to push the Human Rights Act 1998 through Parliament, making it crystal clear that there are certain things the British people can expect as a fundamental right.
However, I have always a felt a certain unease about totally embracing the concept of positive liberty. After all, we may be guaranteed certain fundamental liberties, but how far can they extend? Are we to presume that if the law does not explicitly say we can do something, we are not allowed to do it?
Another concern expressed by many libertarians is that the idea of positive liberty means we expect the state to hand us certain things on a silver platter. Positive liberty has been used as a platform to push through ideas such as that principle that everyone is entitled to a minimum income or standard of living, and for obvious reasons, not everyone is comfortable with the moral hazard this might evoke — if you are guaranteed something, will you be willing to contribute back to society for it? Or will you sit on your bum and collect your entitlements?
Obviously, some balance has to be struck in the real world between positive and negative liberty. After all, it has been said that for you to have freedom, that freedom must first have boundaries in some way.
I think the Constitution of the United States does a good job in striking this balance. Its famous Bill of Rights guarantees Americans certain fundamental, positive freedoms, but at the same time, it explicitly delegates all rights and power not mentioned in the Constitution to individual states, in the name of the people. In other words, you as an individual have the minimum right to everything this Constitution says you may have, but also the right to everything this Constitution does not mention, unless otherwise restricted.
If we rely too much on either positive or negative liberty, we will find the realm of what we are able to do significantly restricted. Overreliance on positive liberty demands a big government willing to legislate on all sorts of issues; overreliance on negative liberty demands a small government that may unnecessarily shirk its responsibilities.