For a long time I thought stalwart meant foursquare and honest; to expand on that, I thought it meant being of sound nature as demonstrated through steady allegiance to a right-minded cause, practice, and/or belief. Aside from allegiances phrases, like party stalwarts or stalwart communist, the only use of stalwart that I remember seeing was in playful or very old-fashioned descriptions of a stalwart young knight or squire or adventurer. Someone with a sword and tights, and with broad shoulders and a firm jaw. I think maybe the jaw misled me. I thought a stalwart young man was firm in his adherence to the high and brave; he was a fellow who lived by a code and faced up squarely to danger. But Merriam-Webster says this: “marked by outstanding strength and vigor of body, mind, or spirit.” Example: “stalwart common sense.”
I could try a tap dance and say that a vigorous and strong nature must be healthy, and a healthy nature must be a fine thing, not cankered, twisted, or bitter. It can’t lack for highness or bravery, and certainly wouldn’t be rich in lowness or cowardice. But Lucifer didn’t lack for vigor of spirit; neither does a shark, neither did Harvey Weinstein. Vigor to health to goodness, by which I mean allegiance to the good, doesn’t work. I can’t say that stalwart has anything special to do with firm principles, not if the dictionary settles things. But so far the dictionary hasn’t. The meaning I like is the same one that people use. Here’s a trace remnant of this use as found in the dictionary definition For stalwart as a noun, we have a “stalwart person,” of course, but also “a stalwart partisan.” The allegiance phrase shows up.
It should since most often the word gets used as a noun, not an adjective. Stalwart knights don’t show up much these days, but the occasional party stalwart lives on when a news writer or historian has to narrate political doings. If the adjective does show up, somebody’s describing allegiance, not rude health and vitality. I can’t prove that, but I shouldn’t have to. You’ve lived the facts; consult your memories. If you take the Merriam-Webster definition word by word, a philosopher can be stalwart if he achieves a breakthrough paradigm, or stalwart if he likes to play racket ball. A llama can be stalwart if it grows fast. A whale can be stalwart too, and the same for an Oscar Wilde epigram—that thing’s fat and heathy with aesthetic accomplishment, ripe proof of human brain resources doing what they’re made for. But people don’t use the word that way.
Checking around, I see that some other online dictionaries come closer than Merriam-Webster. They go with allegiance and allegiance-related ideas, if I may speak broadly, and not so much the robust vigor side of things. But I saw nothing about firm adherence to right-minded beliefs, causes, or practices. I liked stalwart the way I started with it, and now look. It’s less of a word than when we began, and the best-known dictionary in America has a definition nobody bothers to follow.