Editing Foundation (book series) (section)

===''Foundation and Earth'' (1986)===
{{main|Foundation and Earth}}
Still uncertain about his decision, Trevize continues the search for Earth along with Pelorat and a local of Gaia, advanced in Mentalics, known as Blissenobiarella (usually referred to simply as Bliss). Eventually, Trevize finds three sets of coordinates which are very old. Adjusting them for time, he realizes that his ship's computer does not list any planet in the vicinity of the coordinates. When he visits the locations, he rediscovers the forgotten Spacer worlds of Aurora, Solaria, and finally Melpomenia. After searching and facing dilemmas on each planet, Trevize still has not discovered any answers.

Aurora and Melpomenia are long deserted but Solaria contains a small population extremely advanced in the field of Mentalics. When the lives of the group are threatened, Bliss uses her abilities (and the shared intellect of Gaia) to destroy the Solarian who is about to kill them. This leaves behind a small child who will be put to death if left alone, so Bliss makes the decision to keep the child as they quickly escape the planet. Eventually, Trevize discovers Earth but it contains no satisfactory answers for him (it is also long-since deserted). It dawns on Trevize that the answer may not be on Earth but on Earth's satellite – the Moon. Upon approaching the planet, they are drawn inside the Moon's core, where they meet a robot named [[R. Daneel Olivaw]].

Olivaw explains that he has been instrumental in guiding human history for thousands of years, having provided the impetus for Seldon to create psychohistory and also the creation of Gaia, but is now close to the end of his ability to maintain himself and will shortly cease to function. Despite replacing his [[positronic]] brain (which contains 20,000 years of memories), he is going to die shortly. He explains that no further robotic brain can be devised to replace his or which will let him continue assisting for the benefit of humanity. Some time can be won to ensure the long-term benefit of humanity by merging Olivaw's mind with the organic intellect of a human – in this case, the intellect of the child that the group rescued on Solaria.

Once again, Trevize is put in the position of deciding if having Olivaw meld with the child's superior intellect would be in the best interests of the galaxy. The decision is left ambiguous (though likely a "yes") as it is implied that the melding of the minds may be to the child's benefit but that she may have sinister intentions.