*Alive or dead on an individual basis.
*Assume that there are no communication issues, no language barriers, everybody can understand each other. Confucius could speak with Shakespeare who could speak with a 2017 English speaker living in the Midwest.
*Assume that you are meeting people in their physical and mental primes, be they dead or elderly or disabled. Stephen Hawking is not necessarily wheelchair-bound or beholden to a computer for speech assistance.
*The individuals can discuss their entire history/body of work/life. Albert Einstein could reflect on his entire body of work, with the benefits of hindsight and contemporary wisdom.
*You can establish the tone of discourse-all can be mannered and polite and honest and friendly if you choose, or it can be an argumentative and volatile shitshow.* If there's a certain political figure you think is an imbecile, you could stage an intervention for him with the founding fathers.
Now that the technicalities are laid out...
Which five people throughout history would you like to have dinner with, and why?