Time Enough for Love

Time Enough for Love is the capstone and crowning achievement of Heinlein's famous Future History series.
Lazarus Long is so in love with life that he simply refuses to die. Born in the early 1900s, he lives through multiple centuries. Time Enough for Love is his lovingly detailed account of his journey through a vast and magnificent timescape of centuries and worlds. Using the voice of Lazarus, Heinlein expounds his own philosophies, including his radical (for 1946) ideas on sexual freedom. His use of slang, technical jargon, sharp wit, and clever understatement lend this story a texture and authority that seems the very tone of things to come.