This study is a result of examinations about educational effects of abstract thinking on plastic art, which were carried out twice in 1986 and 2003, respectively. First, I gave five lessons to students for the whole of 1986. The first one was "landscape painting" as a text to teach how to depict specifically. Further, I advanced the lessons to the second and third ones in order to develop the first one with a keyword of "extraction of elements", and gave the students the final lesson of "plane structure". Based on this series of lessons, I will debate where sources of pictures to be generated are by leading the establishment of abstract painting. In the second examination conducted in 2003 on the same topic, I narrowed the number of lessons to three and comparatively examined qualitative changes among students, which had taken place for 17 years. I believe that such an examination makes it possible to radicalize the issue of what is important in the future for art education.
