One of the things about Plato is that we really only have his own writings to to get to know him by – mostly, what we would describe today, as his lecture notes. Now he was teaching, not just the impressionable youth of his time, but impressionable youth who’s parents were the rich and powerful. This was a time when the Greeks were feeling their way gingerly towards democracy. They lived in a dangerous world – and a military dictatorship isn’t such a bad thing when instant armed response is a good survival mechanism.
To avoid being accused – and probably executed – for treason and sedition, Plato invented Socrates. This put him in the advantageous position of being able to say that he was only commenting on the lesson, not necessarily preaching it. He developed the character of Socrates to such an extent that a great many people believed he actually existed. Like many a good author since, he found that his creation became more real than he himself. Seeking a suitable and in-character method to dispose of Socrates, he had him arrested and condemned to death, then offered a way of escape – which Socrates naturally refused, opting instead to drink the poisonous Hemlock tea, surrounded by those who were urging him to escape.
However, the vivid, eccentric, cantankerous character painted by Plato is so much a man of that era, that it is entirely possible that he did exist and was a real person.
The picture today, could be Hemlock – or it could be Cow Parsley – or it could be a few Bracken leaves.