2 hourflight but you have to get to the airport early. Then you have to go from charles de gaulle to the city center. It's really much more than 2 hours. Also, in my opinion, it's a lot more stress. I'd prefer to hop on a train from city-center Rome and get dropped off in city-center Paris. Way easier. Also, trains have bar cars. Those are fun. Midnight Trains: sign me up!
https://en.wikipedia.org/wiki/PiHKAL https://en.wikipedia.org/wiki/TiHKAL
It's a fascinating read about the chemist Alexander Shulgin
https://en.wikipedia.org/wiki/Alexander_Shulgin