I cannot explain the doctrine to you in detail, but I can give you the gist in brief.'
"'Speak a little or a lot,
but tell me just the gist.
The gist is what I want.
What use is a lot of rhetoric?'
"Then Ven. Assaji gave me this Dhamma exposition:
"'Whatever phenomena arise from cause:
and their cessation.
Such is the teaching of the Tathagata,
the Great Contemplative.'"
Then to Moggallana the wanderer, as he heard this Dhamma exposition, there arose the dustless, stainless Dhamma eye: Whatever is subject to origination is all subject to cessation.
http://www.accesstoinsight.org/tipitaka ... .than.html
I like the above conversation very much. My limited understanding based on this conversation is the following:
If anything originates at any point of time, it will definitely cease at any other point of time.
Why is that? It is because everything happens due to complex webs of many different causes. When there is any slight change somewhere in one of the causes there will be a change in its effect too. There are inconstruable number of chains of cause and effect in the nature, and these complex web of chains are the reason why everything changes and nothing is permanent.
In fact, changes at the deepest levels (at the levels of atoms or molecules) are unimaginably fast. The perception of relatively stable surrounding is yet another complex illusion of nature.
Only that “thing” can be permanent which does not have any origin or beginning point.
Please suggest if there are flaws in this understanding or if there is anything else I missed.