In The Odyssey, what "laws" of behavior and attitude does Polyphemus violate in his treatment of the Greeks?
Polyphemus, the Cyclops, and son of Poseidon lacks in hospitality which was an unwritten rule among the Greeks. Polyphemus was expected to welcome the visitors and offer them presents, but the Cyclops was cruel and instead fed on Odysseus’ men. Odysseus tried to communicate their expectations, but the Cyclops responded by insulting Odysseus and the gods. Polyphemus averred that the Cyclopes did not pay homage to the gods because they believed they were stronger beings in comparison. Polyphemus further stated that if he was to spare Odysseus and his companions, it would be out of his own will and not out of any regard for Zeus. Odysseus and his men were left with no choice but to plot their way out by hurting the Cyclops. Odysseus and his comrades succeeded in blinding the Cyclops and escaping.
We therefore humbly pray you to show us some hospitality, and otherwise make us such presents as visitors may reasonably expect. May your excellency fear the wrath of heaven, for we are your suppliants, and Zeus takes all respectable travelers under his protection, for he is the avenger of all suppliants and foreigners in distress.’
In the story, examples of the hospitality rule can be seen when Athena in spite of being a stranger, was welcomed by Telemachus in his home. The same gesture was extended to Telemachus when he visited Nestor and Menelaus. In their culture, visitors were welcomed and offered a meal before they stated their aim of visiting. Presents would also be exchanged between the visitor and host before departure.
When Odysseus and his men arrive, Polyphemus is supposed to follow the "hospitality" rule. He is supposed to offer them food and drink, and then ask questions later. The reason for this is that the stranger(s) could be a god or goddess. However, instead, he grabs several of Odysseus' men and eats them. He says that he doesn't have to follow any rules. His father is Poseidon, and he can do whatever it is he wants. His race is in a position where they don't have to work that hard to get what they need. Everything is pretty much given to them. So his attitude is selfish and he answers only to himself. Any other person who would act this way would be cursed by the gods. But since he is the son of Poseidon, he gets away with it.