An adequate theoretical justification of
Why this is right
The support for this comes from the last three sentences of the passage. The author entered with a "But" to challenge the position of the tangible-object theory. She was unhappy that this theory can't accommodate things like live broadcasts of sporting events, but more importantly, she's unhappy that this theory puts more intellectual property value into the person who renders an idea into tangible form than it does into the person who came up with the idea in the first place. In her example of the poet and the friend, she explains how the tangible-object theory would say "the creator" was the friend, since the friend created the tangible object being copyrighted. But the author feels that our common sense notions clearly say the poet is the person who deserves to be considered "the creator". The author's final sentiment of, "there would seem to be no ground for the poet's claiming copyright unless the poet can be said to already own the ideas expressed in the work" is still part of her criticism of tangible-object theory. She's saying, "According to this theory or any other one that reduces intellectual property ownership to the tangible object, the poet would have no right to claim copyright because he didn't actually create a tangible version of his poem. (That's why) we would need to have a way to say that the poet already owns the ideas expressed in the poem." In other words, the author is agitating for a better theory of copyright, one that aligns with our common sense notions that the poet is the creator and the poet is the one who owns this copyright. Thus, an acceptable theoretical justification would need to recognize that you can own ideas, even if you haven't put them into a tangible object.
Skill tested: Author Opinion · how this choice captures the passage's function is the move to repeat next time.