Three Laws of Robotics robot's entire developing consciousness is based. This concept is largely fuzzy and unclear in earlier stories depicting very rudimentary robots who are only programmed to comprehend basic physical tasks, where the Three Laws act as an overarching safeguard, but by the era of "The Caves of Steel" featuring robots with human or beyond-human intelligence the Three Laws have become the underlying basic ethical worldview that determines the actions of all robots. In the 1990s, Roger MacBride Allen wrote a trilogy which was set within Asimov's fictional universe. Each title has the prefix "Isaac Asimov's" as Asimov had approved Allen's outline
Sci-Fi Lullabies albums." Writing for "Vox", Simon Price felt that Anderson wrote some of his funniest lyrics on CD2, on the tracks "Young Men" and "Jumble Sale Mums". Aside from "Duchess", which he called "lazy rubbish," he had strong praise for both discs. The album continued Suede's run of consecutive top ten albums, peaking at no. 9 in October 1997. Despite never placing on any of "Billboard"'s charts, "Sci-Fi Lullabies" had sold 19,000 units in the US by 2008, according to Nielsen SoundScan. Keith Phipps of "The A.V. Club" and Scott Plagenhoef of "Stylus Magazine" spoke of the effort invested in Suede's