Parmenides’s philosophical distinction between the Way of Truth (Aletheia) and the Way of Opinion (Doxa) is one of his most significant contributions to ancient philosophy.
The Way of Truth is the path that leads to knowledge of what truly is, an understanding of the eternal and unchanging nature of reality. On the other hand, the Way of Opinion is the path of perception and belief, where appearances and changes deceive us.
To make this distinction easier to understand, consider the metaphor of a mirror. The Way of Truth is like looking directly at the object itself, seeing its true, unchanging form. The Way of Opinion is like looking at the object’s reflection in a mirror, where the image may change or distort depending on the angle, lighting, or imperfections in the mirror. The reflection represents how our senses and perceptions can lead us astray from the truth.