Sentence:  [T]his first acting principle, this <WSD>entelechia</WSD> is a real life principle (principium vitale) which has a perceiving ability as well, and which is imperishable. And this is just what I consider as the soul of animals. [Leibniz, 1710.] ... A body belonging to a monas which is its <WSD>entelechia</WSD> or soul, comprises together with the <WSD>entelechia</WSD> what we call a living thing, and together with the soul what we call animal. [Leibniz, 1714.] 
Meaning of the word marked with <WSD> tags:  In the metaphysics of (Aristotle) (384–322 <small>BCE</small>) and (Gottfried Wilhelm Leibniz) (1646–1716): a soul; a monad (Leibniz).