The core philosophy of the SGI can be summed up in the concept of "human revolution."
This is the idea that the self-motivated inner change of even a single individual positively affects the larger web of life. A person previously overwhelmed by their suffering can manifest the strength and wisdom to solve their own problems, change the dynamics of their relationships and take compassionate action to help others.
"Human revolution" is a term originally used by Josei Toda, second president of the Soka Gakkai, to describe the process by which individuals gradually expand their lives by chanting Nam-myoho-renge-kyo, conquering negative and destructive tendencies and making the state of Buddhahood their dominant life-condition.
It is this vibrant process of self-reformation--from fear to confidence, from destruction to creativity, from hatred to compassion--and the resultant rejuvenation of human society that forms the essence of Buddhism in the SGI. The inner transformation achieved by each individual will cause changes in that individual's environment, and as the impact of these changes spreads like the ripples of water on the surface of a pond, more and more people will be affected. A change in one person affects others not only in logical ways but through the fact that all our lives are interconnected at the deepest level. It is through this process that the truly "revolutionary" aim of a peaceful world can be achieved.
As Daisaku Ikeda, president of Soka Gakkai International, has written: "A great human revolution in just a single individual will help achieve a change in the destiny of a nation and, further, will enable a change in the destiny of all humankind."