 On all of his bios and obituaries, you'll read something like, he might be the greatest biologist of the 20th century. Right. His work is estimated to have saved about 8 million lives a year. Whoa. Then you'll read something that's like, he was the greatest scientist of the 20th century. We live longer because of him. We live 30 years longer than we did 100 years ago, largely because of the efforts of Maurice Hilleman. Oh, my God. And then you'll come across something that says, he may be the greatest scientist ever.