The concept of "our nature"

Hi.

After you wake up you probably open the curtains and look outside. You may even like to open the window and feel the cool morning air with the dew still on the grass. But is what you see really "outside"? In fact, it is your own mind. As the sun sends its rays through the window, you are not just yourself. You are also the beautiful view from your window. You are the Dharmakaya.
Dharmakaya literally means the "body" (kaya) of the Buddha's teachings (Dharma), the way of understanding and love. Before passing away, the Buddha told his disciples, "Only my physical body will pass away. My Dharma body will remain with you forever." In Mahayana Buddhism, the word has come to mean "the essence of all that exists." All phenomena--the song of a bird, the warm rays of the sun, a cup of hot tea--are manifestations of the Dharmakaya. We, too, are of the same nature as these wonders of the universe.

--Thich Nhat Hanh, Present Moment, Wonderful Moment
From Everyday Mind

This raises an important question, Who are "you"?

Well, his holiness the dalai lama has an interesting answer...

I don’t know the exact position of these Jain schools, but in Buddhism there are two assertions. One assertion is that when you attain nirvana [liberation], then for the rest of that lifetime, the body continues [as do the mind and the self labeled on the continuum of both.] This is known as “nirvana with residue.” But once those appropriated aggregates [of body and mind] that have been obtained from previous karma cease at the time of death, then [with the end of the body] the continuum of consciousness and the self also cease. This is “nirvana without residue.” So at that point there really is no self any more. [The self has come to an end.]

The other assertion, namely that of general Mahayana Buddhism, however, is that there is no reason for there to be a ceasing of the main consciousness. Thoughts that are based on deceptive and distorted cognition come to an end, since there is the opposing understanding that gets rid of their basis. [Correct understanding and distorted cognition are mutually exclusive and so cannot exist simultaneously in one moment of mind.] But there is nothing similar to this that can oppose the clear light mind. Because of that, [individual] clear light minds have no end, and so a self that is labeled dependently on a clear light mind also has no end. Even though the habits of deceptive cognition can come to an end, there’s no reason why a clear light mind should end. Thus, Buddhism has two positions: one that a self has an end and one that it has no end.

http://www.berzinarchives.com/web/en/archives/approaching_buddhism/world_today/what_is_self.html

The important question to start with isn't whether "a self" has an end or not.
Its whether there is an beginning and what/where that is...

May the force be with you.
Fugen