Well, so you say. Your argument is bordering on the absurd here.
I think my argument may seem this way to you because I am using a concept which is frequently used in economics: the assumption of perfect knowledge. Obviously knowledge is not perfect, but it useful to explore its implications.
You seem to be saying theft should be legal as long you steal something you weren't going to buy. What ARE you saying?
No. First of all, you must recognize that there are two harms caused by theft. First, the owner experiences a visible financial loss: he no longer owns an object of value. Second, the owner loses an opportunity to sell the object for more than he himself valued it; we call this loss profit.
Now, physical property has both of these qualities. Intellectual property, on the other hand, has the second, not the first. By copying a cd, I do not destroy the value of the cd I copied. However, if I would have purchased the cd otherwise, but instead I copied it, I have deprived the owner of revenue.
So to answer your question, of course I am not arguing that theft of physical property should be legal, because that clearly deprives the owner of both the value of the object and the value of possible exchange. And as I mentioned previously, I am not even arguing that theft of intellectual property should be legal; that depends on the costs and benefits of granting temporary monopolies to creators.
I am arguing simply on the grounds of morality, not legality. In a world of perfect knowledge and unchanging preferences, I would argue that theft of intellectual property should be legal as long as the thief would not have purchased the intellectual property anyway, because no harm is caused by this act. However, we do not live in such a world. But questions of morality do not require perfect knowledge and unchanging preferences, because people know their own knowledge and their own preferences.
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