The conception of a painting is indispensable and should be carried out to the end, otherwise, it could not be termed as "conception" but only "idea".
Conception is to painting what conception is to writing. What you want to say, how to say it, with what methods and in which steps to say it, and where the theme is, are finally conceived and
implemented in the whole article. So is painting.
When the audiences are catched and attracted by a charming painting work, It must have a clear realized conception, a set of unified and definite
grammar, a unique theme and rich levels, any of which is indispensable and not omissible. Therefore, painting is the outcome of both vision and thought.