"Hesiod" is the name of a person; "Hesiodic" is a designation for a kind of poetry, including but not limited to the poems of which the authorship may reasonably be assigned to Hesiod himself.
The Roman bronze bust, the so-called Pseudo-Seneca, of the late first century BC found at Herculaneum is now thought not to be of Seneca the Younger. It has been identified by Gisela Richter as an imagined portrait of Hesiod. In fact, it has been recognized since 1813 that the bust was not of Seneca, when an inscribed herma portrait of Seneca with quite different features was discovered. Most scholars now follow Richter's identification.
The first known Writers to locate Homer earlier than Hesiod were Xenophanes and Heraclides Ponticus, though Aristarchus of Samothrace was the first actually to argue the case. Ephorus made Homer a younger cousin of Hesiod, the 5th century BC Historian Herodotus (Histories II, 53) evidently considered them near-contemporaries, and the 4th century BC sophist Alcidamas in his work Mouseion even brought them together for an imagined poetic ágōn (ἄγών), which survives today as the Contest of Homer and Hesiod. Most scholars today agree with Homer's priority but there are good arguments on either side.
He viewed the world from outside the charmed circle of aristocratic rulers, protesting against their injustices in a tone of voice that has been described as having a "grumpy quality redeemed by a gaunt dignity" but, as stated in the biography section, he could also change to suit the audience. This ambivalence appears to underlie his presentation of human history in Works and Days, where he depicts a golden period when life was easy and good, followed by a steady decline in behaviour and happiness through the silver, bronze, and Iron Ages – except that he inserts a heroic age between the last two, representing its warlike men as better than their bronze predecessors. He seems in this case to be catering to two different world-views, one epic and aristocratic, the other unsympathetic to the heroic traditions of the aristocracy.
Greeks in the late 5th and early 4th centuries BC considered their oldest poets to be Orpheus, Musaeus, Hesiod and Homer—in that order. Thereafter, Greek Writers began to consider Homer earlier than Hesiod. Devotees of Orpheus and Musaeus were probably responsible for precedence being given to their two cult heroes and maybe the Homeridae were responsible in later antiquity for promoting Homer at Hesiod's expense.