Socrates

Socrates was a classical Greek philosopher, and teacher of Plato, who lived during the 5th century BC. During that time, the immortal Flint had known Socrates personally. 

In the eponymous play, Cyrano de Bergerac was an admirer of Socrates and hoped he'd meet him and Galileo Galilei after his death. 

A holographic simulation of Socrates was among the historical personality profiles studied by The Doctor, in 2373, during his attempt to expand his personality sub-routines. In the simulation Socrates played kal-toh against T'Pau, as The Doctor conducted his interviews with the other historical figures.

When The Doctor's alter-ego, created from the combined 'dark threads' of the sub-routines of these historical figures, began to destabilize his program, he took to altering their sub-routines, to solve his own issues. His "work" was later discovered by Kes, when she found the upper body of the Socrates hologram laying on the holodeck floor.