Part I Theoretical Background.- 1. Electromagnetism.- 2. Quantum Mechanics.- 3. Quantum Computational Chemistry.- Part II Background of Ferroelectricity.- 4. Basics of Ferroelectricity.- 5. History of Ferroelectric Perovskites.- Part III Origin of Ferroelectricity.- 6. Perovskite Titanium Oxides.- 7. Materials Design.- Part VI Summary and Outlook.- 8. Summary and Future High Speed Memory.