By some accounts (see, for example, this one), the modern-day origins of Saint Valentine’s Day go back to the 14th Century, and according to this report in The Scotsman, this amorous occasion was celebrated in Scotland as far back as medieval times. As it happens, during the pandemic I set out to investigate whether the great Scottish moral philosopher and political economist Adam Smith, the author of two of the most influential works in the English language and a lifelong bachelor, had ever fallen in love. My full report on this matter, which is titled Adam Smith in Love, is available here. (For a summary of my researches, see my blog post “Adam Smith’s lost loves“.)
prior probability 
You got me with that title! Hah, you make a good case for him entertain love in his life–but was it affairs or unrequited?
most likely Platonic or unrequited, but the years 1746 to 1748 (when Smith was still in his early 20s) are a total mystery
Maybe a lost document will be found!
That is my hope!
Enrique, I believe you have truly carved out a unique niche in the Adam Smith scholarship.
thanks for your kind words! I am a huge Adam Smith fan, and the more I learn about Smith the more I admire him!
I can see that. He does seem more dynamic the more we learn about him.