With PARMENIDES began what is called, in more specific terms, true Philosophy. 
The Eleatic, and his Poem, constitute a "beacon" whose light illumined Plato and even Aristotle, and consequently all the philosophers that followed. 
Parmenides laid down several fundamental philosophical principles: 

1.    The Being as foundation of all the existent
2.    The principle of identity, Being is identical to itself
3.    The principle of non-contradiction
4.    The principle of a-temporality or eternal present
5.    An initiatory philosophical vision of an experiential order

For Parmenides the primary aim is the research for the ultimate Truth, and he, Parmenides, has introduced the mortals to the straight path of wisdom: 

"... and here immediately through the gate the maidens steered the char­iot and the mares straight onto the road. The Goddess kindly welcomed me and took my right hand in hers and addressing me she uttered so: "O young companion, led by the mares and immortal charioteers, you come to our home: rejoice, for no adverse Moira sent you to travel this path - which is far from the way traveled by men - but Themis and Dike" 

The transition from one state of consciousness to another higher one, in a completely objectivistic society, is a revolutionary event, and also of this consists Parmenides' greatness and importance in contemporary life.