Although Hawking was known for his work on cosmology and black holes, his final book is a "reflection of his humanity" and his hopes that unsafe new technologies could not just destroy, but also unite and revolutionise human life.
In his answer, Hawking emphasised the importance of education and research, lamenting that funding for science was being significantly cut.
"What lies ahead for those who are young now?"
"With Brexit and Trump now exerting new forces in relation to immigration and the development of education, we are witnessing a global revolt against experts, and that includes scientists", Hawking said.
He also recognised that science is yet to overcome some pretty major challenges - including climate change, overpopulation, species going extinct, destruction to forests and the death of the oceans.
He says that in the next 50 years, we will come to understand how life began and possibly discover whether life exists elsewhere in the universe.
Hawking continued: "It matters that you don't give up".
How do we shape the future?
Referring to techniques such as DNA-editing system Crispr-Cas9, which allows scientists to edit defective genes, the author of the internationally bestselling A Brief History of Time said superhumans would pose problems for "unimproved humans" who will not be able to "compete". Thus they can modify their DNA and their children, improve memory and resistance to disease, and life expectancy and improve intelligence.
Mr Hawking added: "Presumably they will die out, or become unimportant. Instead, we get a race of people, who themselves are designing more and more improved", - he stressed.
However, his theories from the Brief Answers to the Big Questions also drew the attention to several critics, like the astronomer Lord Rees, an old friend.
He predicted that even if laws were passed to kerb genetic engineering there would always be people prepared to break any rules which would spark the rise of superhumans.
He was diagnosed with motor neurone disease in 1963 at the age of 21. In June, his ashes were buried in Westminster Abbey, between the graves of Charles Darwin and Isaac Newton.
Hawking's daughter Lucy, who attended the book launch, said hearing her father's unmistakable voice had been "very emotional". I think that when we die we return to dust, ' he explained.