Elon Musk cited free speech concerns and the future of civilization as the reasons he wants to buy Twitter Inc., saying the social-media platform should be more transparent about how and why it promotes content.
Mr. Musk, who disclosed a large stake in Twitter last week, offered earlier Thursday to buy the rest of the company in a deal valuing the social-media site at more than $43 billion, calling the bid his “best and final offer.”
