While Plato approaches metaphysics from a transcendental lens that hones in on basing our beliefs through reasoning, Aristotle approaches the fundamental nature of reality through an observational and phenomenological lens.
Concerning what we may observe through his dialogues, Plato’s metaphysics is most clearly observed through his discussion of the “forms” and related concepts. Throughout the readings, the notion of the “forms” are quite prominent during Diotima’s dialogue concerning eros in The Symposium. According to Plato, the idea of eros is something belonging to neither man nor god, but, rather, something in between as some sort of “spirit”.[1] At its most fundamental, eros is something already beyond man. To be precise, it is a spiritual energy between man and god. According to Plato, at first, man directs their “attention to beautiful bodies” and falls in love with “one individual only”.[2] Through contemplation at length and pondering, they will come to love “the beauty in souls” and then, eventually, “that particular knowledge which is knowledge solely of the beautiful itself”.[3] This spiritual energy called eros falls down unto man as man develops, contemplates, and reasons. Through this exploration of the “form” of eros, Plato hints towards a transcendental metaphysical view of the world that goes beyond the material and towards fundamental ideas that exist beyond.
In contrast, Aristotle explores fundamental questions purely through what we can observe as beings that exist in the world. Jonathan Lear notes how Aristotle begins his Metaphysics by speaking of the vague impulse wherein “all men by nature desire to know” and discussing the “delight we take in our senses”.[4] Aristotle describes how the senses are responsible for the process of “[bringing] to light many differences between things”.[4] Through the observation of phenomena in the world, “the world prompts us to inquiry;” man follows the desire to know and uncover the truth.[5] Through uncovering the world, man ultimately “comes to understand who he is”.[6] This phenomenological approach to metaphysics is more grounded in the material world than Plato’s more transcendental view. Therefore, Aristotle implies that the quest for knowledge is fulfilled through a rigorous, observational, and methodical inquiry of the world man exists in.
Ultimately, the fundamental difference between Plato’s and Aristotle’s metaphysics lies between the transcendental and that which we as human entities within the world can observe.



References

1. Plato’s The Symposium translated by M. C. Howatson. Cambridge University Press, 2008. 202e.
2. Plato’s The Symposium translated by M. C. Howatson. Cambridge University Press, 2008. 210b.
3. Plato’s The Symposium translated by M. C. Howatson. Cambridge University Press, 2008. 211b.
4. Jonathan Lear. Aristotle: the desire to understand. Cambridge University Press, 1988. Page 1.
5. Jonathan Lear. Aristotle: the desire to understand. Cambridge University Press, 1988. Page 7.
6. Jonathan Lear. Aristotle: the desire to understand. Cambridge University Press, 1988. Page 8.