I have come to consider mortar & pestle pharmacy signs as representing the pestling of the Hippocratic oath by a market-driven world, aided and abetted by existential fear.
One of my earliest first memories was from my pram: above me I could see a golden mortar & pestle. I still vividly recall wondering: why a jar of sweeties was raised so high?!
The following post tells you more about Gilbert Farie and the world he faced (click on image of Robert Louis Balfour Stevenson):
From “Living to Tell the Tale” by Gabriel García Marquez: