According to Parmenides, reality is unchanging, singular, and eternal. He fundamentally differed from the views of earlier philosophers by asserting that change and plurality are mere illusions. Parmenides believed that what truly is, must be, and cannot not be. This means that existence is a singular state that cannot come into being or cease to exist.
In his poem, Parmenides emphasizes the importance of reason over the senses. He argued that our senses deceive us, leading us to believe in a world of change and diversity. Instead, through rational thought, one should arrive at the understanding that there is only one reality—one, unchanging, and undivided. This perspective leads to the conclusion that the essence of reality is a state of being that is consistent and immutable.
Ultimately, for Parmenides, the way of truth is a path to recognizing this singular, unchanging reality, while the way of opinion involves the deceptive multiplicity of appearances in our everyday experiences.