Here's why:
* Literary Works: The Three Laws are part of Asimov's science fiction stories and were not intended as legal or technical principles.
* Public Domain: The concept of the Three Laws is widely known and used in various media and discussions, making it difficult to trademark.
* No Commercial Use: Asimov didn't seek to commercially exploit the Three Laws, which further reduces the likelihood of them being trademarked.
However, if you want to use the exact wording of the Three Laws for a specific product or service, it's best to seek legal advice to avoid potential copyright or trademark infringement issues.