LEHTSC2007 attended by 110 scientists was held at AIST, Tsukuba, Japan, during October 31-November 3. As autumn deepened in late October, the leaves of the beautiful Ginkgo trees changed colors during the conference, from verdant green to bright yellow. However, unlike the Ginkgo trees, the conference proved that the "truth" never changes.

As Chairman of the Organizing Committee, I would like to express my greatest appreciation to all invited speakers, oral and poster contributors for participating in the conference. LEHTSC2007 confirmed that the "truth" never changes, even after the discovery of high temperature superconductivity (HTSC) 21 years ago.

LEHTSC2007 program was carefully designed to mark the milestone since the discovery. All speakers gave extraordinary lectures which were followed by active comments and discussions. The subtitle of the conference "Spin, phonon or the third way ?" unfolded as the conference progressed. Starting from well organized reviews of HTSC, the conference developed into detailed lectures on phonon (lattice).

The atmosphere of the conference was open and casual so that everyone, including young scientists who will take on future responsibility to enhance our work in the 21st century, would have the opportunity to participate in constructive discussions.

"Spin or phonon" has now become an oversimplified controversy of the past and the time has come for us to examine and seek a third way. A higher level of understanding must be reached by putting aside the idea of a purely electronic (magnetic) mechanism just as a simple phononic mechanism is unlikely.

With this aim, the next question will be how to reach an unified understanding, that is the establishing of realistic models. Some scientists are now incorporating "missing ingredients" or the electron-lattice interaction, while others are trying to create novel mechanisms which indeed take into account interplays and cooperative natures. Great patience will be needed, but we have certainly started on our journey.

We hope to meet our past opponents on the top of the HTSC mountain, hopefully, after getting to the top first. We are optimistic that following conferences will be equally successful and contribute to shortening the time for the discovery of HTSC mechanism. We look forward to seeing you all at the peak.

Hiroyuki Oyanagi,
Representing the organizers of LEHTSC2007