Absolutely genuine or authentic; pure or untainted. A reference to the character Simon Pure in Susannah Centlivre's 1717 play A Bold Stroke for a Wife. The new leader is promising to bring simon-pure democratic principles back into the political discourse.
Absolutely genuine, quite authentic, as in That laboratory test was simon pure; none of the specimens was adulterated. This expression comes from the name of a character in a play, Susannah Centilivre's A Bold Stroke for a Wife (1717), who is the victim of an impersonation but turns up in the end and proves that he is "the real Simon Pure."
The real thing, the genuine article. This expression comes from the name of a character in an early eighteenth-century play, Susannah Centilivre’s A Bold Stroke for a Wife (1710). In it, Simon Pure, a Quaker, is the victim of an impersonation by Colonel Feignwell. However, the Quaker turns up in time and proves that he is “the real Simon Pure” (5:1).