According to Aristotle the changes which happen by nature are caused by their "formal causes", and for example in the case of a bird's wings there is also a final cause which is the purpose of flying.
Menurut Aristoteles, perubahan-perubahan yang terjadi alami disebabkan oleh "sebab formal" mereka; contoh untuk kasus sayap burung ada pula sebab final, yaitu untuk terbang.