"Origins of words" by Susie Dent, Countdown 24/01/18 (being in one's element)

I had a tweet from Chloe Wrtight, who asked of the background of being in one's element, if you're in one's element. And to answer this, you need to look back to the very elements that were once believed to be the make-up of all human beings. The primary elements being earth, fire, air and water. And, as regular viewers will know, every human being was classified according to their humorous disposition, the humorous here have nothing to do with comedy or wit, and everything to do with bodily fluids and the balance with which they existed in the body. But if you tke those bodily humours, they were always thought to have one corresponding element, whether it was, as I say, air, fire, water or earth, and every human being was thought to have a particular affinity to one of those and they weren't always obvious, either. So a salamander, for example, was thought to exist in fire, so quite curious medieval beliefs, there. But to go back to those corresponding elements, somebody who was inrtospective, quite creative but prone to melancholy... Melancholy, as you know, meant black bile, because a melancholy person was thought to have too much of it. These people were supposed to be ruled by the cold and dry element of earth. The wiry, often red haired for some reason, ambitious and choleric person was dominated by fire, they were hot and dry. And the sluggish, slightly phlegmatic, and perhaps slightly tubby person, was sain to be influenced by water. Whereas someone who was sanguine, red-cheeked, optimistic, they enjoyed all the healthful benefits of air. Obviously there were quite sort of neat categories that they thought people existed in, but it wasn't always the case. Clearly not all of us are red haired or optimistic all of the time, so they were a little bit too neat, and the truth was that... We all need in order to keep a happily existence, to have these elements and  thase humours in good balance. But it was quite interesting, because the phlegmatic person, someone who was full of phlegm, it was thought, and stiocally calm, as a result, was advised not to eat fish, because they would make the water element go overboard, if you'll excuse the pun,  so that easn't a good thing. And someone affected by melancholy was told to avoid eating vegetables because then the pull of the Earth would become too strong, so it really informed so much, not just beliefs as to personality, but also medicine, dietary habits, all that kind of thing. Add all of the characters in the writings of Shakespeare and his contemporaries reflect this view of the world, and references to being in your element date all the way back to the 16th century and beyond, so it was a really core part of understanding the world ant the universe, was to be in one's element, and that was crucial for happy life.