Four lines are enough for Edward Thomas to turn a compliment into a quiet correction. The poem begins by praising the wise man, who knows "full well" when to laugh because he knows "what is truly laughable". Then comes the word "But", and the praise is outflanked. There is someone "wiser" still, whose wisdom lies less in having a correct sense of humour than in what he does when "the foolish" laugh.
The central idea is that knowing is not the highest form of wisdom. The first kind of wise man is a connoisseur who can tell the genuinely funny from the merely silly. The second is more flexible. He "laughs also", joining in, "Or holds his laughter" when the foolish laugh. The poem never says which choice is better, and that silence matters. Joining in could be a kind of fellow feeling, and holding back a kind of tact or caution, but the poem leaves the reasons unspoken. What it seems to value is judgment in the moment, not a rule.
The construction supports this. The poem is in unrhymed iambic pentameter, with ten syllables to a line and a steady, conversational beat. With no rhyme to round things off, it sounds like a considered remark made aloud, the kind of saying one might remember. The grammar splits it into two halves. Lines one and two are about knowing: "knows" appears twice, and the sentence is balanced and sure of itself. Lines three and four turn to action: "laughs", "holds", "do". The poem moves from the wise man's head to his behaviour, and that shift is its argument in miniature.
Thomas also works with a tiny vocabulary. The word "laugh" comes back in four forms: "laugh", "laughable", "laughs", "laughter". "Wise" becomes "wiser". Because the words barely change, the small differences carry the meaning. "Laughable" means able to be laughed at, a judgment about the world. "Laughter" is the thing itself, something a person produces or withholds. The poem quietly shows the difference between assessing a joke and joining a room.
The one physical image is easy to miss. To "hold" laughter is to treat it as something with weight, like a breath or an object kept in the hand. After two lines of abstract knowing, the verb is suddenly bodily, and it makes restraint feel like an effort. The wiser man is not simply lacking a sense of humour. He is containing one.
Some of the poem's pleasure lies in its ambiguity. "Laughs also" can mean he laughs along with the foolish, or that he laughs at what is truly funny and at their jokes too. The final "when the foolish do" is compressed in the same way. "Do" stands in for "laugh", so the line reads as "holds his laughter when the foolish laugh", though the grammar is sparse enough to make you check. Nor does the poem say why the foolish laugh. Judging by the first line, they may be laughing at the wrong things, which would make the wise man's private standard quite different from theirs. Yet the wiser man does not enforce it. He lets other people's laughter count for something, which suggests that being sure of your own taste is a small wisdom compared with knowing how to live among other people.
There is a mild irony in the ending. The poem closes on "the foolish", not on the wise. After lines of praise for the discerning, the last word goes to the people who were supposed to be beneath notice. The flat little verb "do" lands without ornament, as though the poem were declining to sneer.
Edward Thomas, an English poet killed in 1917 during the First World War, is remembered for plain-spoken, unshowy verse, and that plainness is visible here. There is no decoration and no raised voice. What makes the poem worth reading is how much it packs into so little space. It starts as a flattering portrait, then dismantles the pride in being right and replaces it with something harder: the sense of when, and with whom, to laugh.