ESSENCE:
What a thing is. The internal principle whereby a thing is what it is and not something else. Sometimes essence is said to be the same thing as being, but being merely, affirming that a thing is, without specifying its perfections. Essence is not quite the same as nature, which adds to essence the notion of activity, i.e., nature is the essence in action. Or again essence is substance, but not all essences are substantial because accidents also have an essence. (Etym. Latin essentia, essence, being.)
I have to tell you now I am wrestling with this one.
Why do we need this definition first of all?
We need them so we can talk about the things that exist in the world. It is true that the terms nature, essence, substance are somewhat interchangeable, even in Aristotle and Thomas. Here is how I explained it on another thread, " Re: What does, " the nature of a thing " mean?
"… it seems that nature, essence, substance are used similarly and at two levels of reality, the first being the ground or source all a beings structure, activities, powers, etc. The second being the " external " appearance that can be touched, seen, experienced. Each may be called a " quiddity, " but at different levels.
Man by definition is a rational animal. That is his quiddity, that is what he is. But the definition still applies whether we are talking about Second Substance ( nature, essence at the level of matter, form, and act ) or First Substance, the thing we see and expericne and lay hands on.
It is the same quiddity viewed from different perspectives.
From post # 12 thread above: " "Nature properly speaking is the essence (or substance) of things which have in themselves as such a principle of activity (Aristotle, “Metaphysics”, 1015a, 13). By a process of abstraction the mind arises from individual and concrete natures to those of species and genera. " Or stated differently, " Nature is the principle of motion/change and rest in those things which are natural ( as opposed to accidentally compounded or man made ). " ( Physics ).
But to be most precise it is the substantial form of a thing and its particular matter which is the primary source of all the properties, activities, powers, etc of an individual substance. But in practice " Nature " is used most often when considering the thing as it acts. While " Essence " and " Substance " are used mostly when considering a thing as a stable entity. We should be able to determine the precise meaning from the context.
Linus2nd
Linus2nd