Gosh! I thought man’s essence was to be a “rational animal”.
Jeeze, I hope you were just funnin’ us! LOL, If man is essentially a ‘rational animal’, how come thing’s are the way they are?
There is a lifetime of reading just to look at all the arguments as to what constitutes the essential man, or what attributes make’s us distinct from other animals. About the only thing most philosophers can agree on is sentience. Self awareness. Although there is now a mounting stack of evidence suggesting than some of our near-relatives also have some form of self awareness, sentience is considered to be the province of man.
Of course, there is also a good bit of evidence than not all men are sentient. 
JT
phrygianslave the wise,
I’d have to agree with, “god created man in his own image.” The reason is because, I’m a product of my parents who are essentially no different than me. Therefore, for us human beings, God, if He created us then He would have to be like us too but it would not be limited to that alone 'cause He’d be more. But it would be enough for us to know that He’s like us to understand Him and us.
And where you say that, “Does man have an essential nature? If he does could part of this essential nature require of him that he become more and more godlike?”
I’d have to say that a human’s essential nature is to be human and so ‘his essential nature requiring him to become more and more godlike’ would mean nothing because God is like us, our feelings, our sentiments, our thinking and our predicament. Therefore, the person who is himself I would say would be more Godlike than the one who aspires to be Godlike.
I have always thought the essential nature of anything was what made it itself. So the essential nature of man is to be human, not to be God or Ape. What is essentially human? Well certainly imperfection and finite knowledge. Man can imagine perfection and I might agree that is how the theory of God was developed(by taking imperfect and finite and inserting NOT) so I think Descartes was wrong about his proof of God. Man can imagine perfection, and man can see in himself the potential for perfection. He cannot see this same potential in an Ape. Neither can he see any potential for perfection in God, because God is NOT imperfect and NOT finite, so God has no potential for perfection but rather God is already actually realized infinite perfection. So man can imagine God and can clearly and distinclty see that if there is God, then man is not God. Man can imagine infinite perfection and man can see himself making progress toward perfection. However, there is one thing that man can not imagine ever happening. Man can not imagine himself ever arriving at infinite perfection. Man can see himself progressing but never arriving. Man can see his knowledge increasing but can never imagine arriving at infinitely perfect knowledge.
So I would say that man’s essential nature is to be human, finite and imperfect, capable of imagining infinite perfection (the theory of God), and (unlike the Ape) capable of making unlimited progress toward infinte perfection, but not capable of ever arriving at the God-like state where man no longer has any potential but is already actually realized infinite perfection. So it is man’s essential nature to have unlimited potential for perfection but to never realize infinte perfection.