http://mattbruenig.com/2013/11/10/no-serious-there-is-no-non-political-definition-of-theft/
"The correct view on the naturalness of distribution is that it isn’t natural. Who gets what is all made up and we can make it up how we want. That’s not to say it’s all arbitrary and all ways of doing it are equal. It is to say that you have to come up with normative principles for your preferred distribution that don’t assume that things inherently and naturally belong to people. An argument that relies on such an assumption is always invalid."
I'll assume when you say 'things' you mean 'rivalous property'. Because you didn't give ANY definitions, to avoid confusion, I'll define 'property' as the exclusive right to the control or use of a rivalrous good. No matter what the 'normative principles for your preferred distribution', property rights still exist, and your argument therefor still assume that 'things' inherently and naturally belong to people. No matter the scenario, one person or group of people, is/are making a claim to property.
"Sometimes people make an argument that seems to not rely upon this assumption but secretly does. It goes like this: if I buy a home and then you change the distributive rules at some point so it doesn’t belong to me anymore, then you really have taken from me. The upshot of this argument is that you don’t need a normative theory of entitlement or a belief in a natural distribution to say something is confiscatory. But it fails."
"What it reduces to is the claim that all changes to distributive rules are somehow theft because they change what would belong to people relative to the no-change baseline. The house example is a good one. Suppose we change the rules so the house doesn’t belong to you anymore (so it belongs now to someone else or some other group of people), and then we change the rules back so that it does belong to you again. If you actually believed that changing the rules was theft, then you’d think this was two bouts of impermissible theft."
But it's not two bouts of impermissible theft. Since we're talking about normative principles, the normative principle in society for theft would be 'the use or threat of force when claiming a right to property that wasn't voluntarily agreed upon'. The first scenario was the normative principle. When you say 'we change the rules' you mean 'we use government force against you'.
I'll argue that not only is changing the rules theft, but it's also slavery. If I buy a home for $100,000 and it took 3 years of work and the resulting income to pay for that home. Then one day you 'change the rules' (use force against me) and take that property from me and give it to yourself, you are not only claiming a property right in the exclusive use and control of that home, but also in my body for the 3 years of work it took to afford that home. Since you used force to take the fruits of my labor, I was forced to work for your personal gain, slavery.
Based of the theory of estoppel, if a person or group of people use force to claim a right to property (theft) they are claiming a normative principle that it is OK to use force to take property, and therefor have no complaint if force is used against them in the claim of, or reclaim of, that property. Changing the rules back can't be said to be theft, as this person would have no complaint against the original owner taking it back. It is the returning of stolen goods, the reclaiming of property that you did not voluntarily agree to give up in the first place.
"But a person who claims changing the rules in the first case is theft doesn’t believe changing the rules back would also be theft. They believe that the first rule change was theft and the second rule change was distributing the house back to its rightful owner. It was untheft. But that indicates then that they have some other idea of what deeply and truly belongs to people, and that it is this idea that actually underlies their claim of theft. They don’t actually believe rule changing is theft. They believe rule changing that is inconsistent with their theory of deep entitlement is theft. But then that just pushes us back into a totally normative debate about who is entitled to what. We never escaped into some neutral world where we can decide something is theft in and of itself without reference to a normative theory of entitlement."
Any time you use force to claim a right to property, that is theft. Any time you use force to claim the fruits of someone's labor, that is slavery. Neither of those statements are my 'theory of deep entitlement', these are both not only normative principles within society, but literally the definitions of the words. The second rule change wasn't theft because the second owner didn't have a valid (or moral) claim to that property, they used force AND made the original owner their slave for the time and labor it took to get that property, and therefor have no complaint. Theft is only theft because one party has a complaint against the other over the control and use of a
rivalrous good. If there is no complaint, or if one parties complaint is invalid (which it would be because they established a principle that it is OK to take property without the others voluntary permission when they did it), then there is no theft. So, no complaint, or valid complaint, over the use and control of a rivalrous good = no theft.
"You can still argue for whatever distribution you prefer even if it is an extremely unequal one."
Your argument would be a self-contradiction. If you are peacefully arguing with someone that they have no right to the control and use of rivalrous property, you are
attempting to reason them into voluntarily giving their right to the use and control of rivalrous property to you, so you can have the right to the use and control of that property. Therefor, in a peaceful argument over rivalrous property a normative principle is established between both parties that they only have the right to the use and control of rivalrous property that they acquire by voluntary means from the other party. Individual property rights and ultimately, libertarianism, is presupposed by the act of peacefully arguing over the right to rivalrous property.