Aristotle's Metaphysics, Ethics & Hellenistic Philosophy
Aristotle's Core Philosophical Concepts
Metaphysics: The Study of Being
Being and Substance
Aristotle observed that the concept of "being" has multiple meanings. However, he argued that these meanings ultimately relate to a primary concept: substance (ousia). Substance is fundamental because it exists independently, serving as the underlying subject for its various properties or accidents (e.g., quality, quantity, relation). Accidents cannot exist on their own but must belong to a substance.
Categories
The Categories represent the different fundamental ways predicates can apply to a substance, classifying the types of accidents and also including what Aristotle termed secondary substance (universal concepts like genera and species, e.g., "human"...


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determine a parallelepiped whose height is the distance between the two lines.
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