How did Aristotle explain potentiality and actuality?

In Aristotelianism, the concepts of potentiality and actuality are central to understanding change and the nature of substance. Aristotle viewed substances not as static matter, but as intelligible structures or forms embodied in matter that are actively striving to reach their natural state.1

• Potentiality: This refers to the capacity of a substance to develop or become something else. It represents the inherent possibility within a thing to attain its natural form.1
• Actuality: This is the state of a substance when it has achieved its natural form, effectively becoming a proper specimen of its kind.1

Aristotle’s system is fundamentally teleological, meaning that change is explained by the purpose or end toward which a substance moves. Rather than being driven solely by external mechanical forces, substances are drawn toward their own perfection—seeking to be in actuality what they are potentially. This process is likened to biological growth, where an organism develops from an imperfect state, such as a seed or embryo, toward the mature, fully developed form of its species.12