De omnibus dubitandum
Apparently “Confessions” were semi-jocular questionaires that were popular in Victorian England and filling them out a common pastime in many families. Marx apparently filled them out several times at the behest of his daughters. In both extant questionnaires his answer to Favourite Motto was De omnibus dubitandum (Doubt everything). I came across a post card, that I now use for one of my computer desktops, when touring Marx’s childhood home in Trier. I immediately felt an affinity to the sentiment.
So if you don’t mind having a notorious socialist as your muse, I suggest everyone embrace this as their new motto in this age of misinformation and outright lies.