The central one is that the world is a garden full of weeds. "Things rank and gross in nature possess it merely." Thus Claudius poisons Hamlet, Sr. with weeds. "Something's rotten in the state of Denmark." "If the sun breed maggots in a dead dog / Being a God kissing carrion..." Hamlet compares Claudious to a "mildewed ear." And Opehlia dies in weeds and water. But the play is full of them. When Hamlet in Act IV says to the Captain: "Two thousand souls and twenty thousand ducats / Will not debate the question of this straw" he compares a plot of land to a straw--a metaphor suggesting the insignificance of world matters. Almost any speech yields more.