The Iliad reveals much about Greek culture as it existed before the Classical Age. As other contributors have already pointed out, we see within this poem the primacy of warfare in the era. Additionally, the Iliad reveals much about the religious life of the early Greeks: how sacrifices were carried...
The Iliad reveals much about Greek culture as it existed before the Classical Age. As other contributors have already pointed out, we see within this poem the primacy of warfare in the era. Additionally, the Iliad reveals much about the religious life of the early Greeks: how sacrifices were carried out, for example, or beliefs about the power of fate. Indeed, destiny is a critical theme within the Iliad and a power before which even Zeus must bow.
At the same time, one might have a sense when reading the Iliad that, for all that warfare and feats of glory may have been prized, the poem does seem to ruminate on the tragedy of warfare. We see this in book 6, for example, in the famous scene wherein his wife, Andromache, begs Hector not to fight, on account of his family. (We also receive, in this same scene, a glimpse into the terrible fate which might await his family, when Troy would finally fall.) Additionally, one can point towards Achilles himself in self-imposed exile. While it is true that this exile is driven largely out of injured pride and his hostility towards Agamemnon, it is also worth noting that there does seem to be a more generalized disillusionment with war, and the bloodshed resulting from it. As he says in book 9,
For nothing, as I now see it, equals the value of life—not the wealth they say prosperous Ilium possessed in earlier days, when there was peace, before the coming of the Greeks, nor all the treasure piled up behind the stone threshold of Phoebus Apollo in rocky Delphi. Cattle and fat sheep can be lifted. Tripods and chestnut horses can be procured. But you cannot lift or procure a man's life, when once the breath has left his lips. (Iliad (Penguin Classics Ed.) trans. E. V. Rieu, revised and updated by Peter Jones and D. C. H. Rieu.)
In a sense, these scenes suggest that the Greeks possessed a degree of nuance in their understanding of personal glory and feats of heroism. They seem to have been aware of the tragic and destructive elements embedded within such a culture.
Finally, as was previously stated in other answers, we get a vivid sense within this poem of the brutality of this culture as it would have been experienced by women. Consider the treatment of Chryseis and Briseis, who are reduced to concubines by the victorious Greeks. To this, one might also add that the overall picture it paints of the world is a brutal one, where a city, if defeated, would face slaughter and enslavement of its population.