The article is an attempt to define reduction as the beginning of philosophy. The author considers such questions as: What motivates a phenomenologist to do reduction? Can one speak of philosophy before reduction? What is the essence of reduction? To answer these questions the author refers to Husserl, Fink and, Patočka, and tries to show that reduction is to be understood as an unmotivated expression of philosopher's will to overcome evidence inherent to natural attitude. The author argues that reduction enables one a problematization of the world as such. Finally, reduction is defined as an attempt to take doing philosophy seriously.