The End and Again the Beginning

Why did Alexander the Great first go to Persia and then to India and Central Asia? What did he need there? According to the theory of Lev Gumilev — nothing! “All these great wars are not waged because someone needs them (least of all their participants), but because there exists something that I have called 'passionariness' — it comes from the Latin 'passion'.” Lev Gumilev proves that this is quite a real motive for the behavior of not only Alexander the Great but also Cornelius Sulla in Rome, Hernan Cortes, who went to America at the risk of his life, and Napoleon, who sought not material well-being, but unlimited power over the world.
Lev Gumilev 'saw' his theory while sitting in a cell: a beam of light fell from the window onto the cement floor. The author was struck by the idea that passionariness is energy, just like that which plants absorb.
The basis of the book is the ages of the ethnic group, the life cycles of the ethnic group, the emergence of passionaries, which generate ethnic processes.