Modern life is all about the "pursuit of personal pleasure", a concept that would have been alien to young people during the Great War, he suggested.
Speaking at a conference for schools on the war, Mr Paxman, who recently presented the BBC television series Britain's Great War, says this attitude is one of the reasons he believes such a conflict will not happen in the future.
"There was what is notably absent now - another thing that I think makes this sort of conflict unimaginable in the future - there was a sense of duty," he said.
"If you consider the way we lead our lives now, we lead our lives essentially in an atomised fashion, pursing personal pleasure.
"It's all about personal choice; do what you want, please yourself.
"This was a world that was unknown to young people in 1914, 1915, 1916."