Arnol'd's ODE book distinguishes itself from the dozens of others by its emphasis on the qualitative and geometric theory rather than the quantitative theory. His aim is to analyze and describe the behavior of systems, rather than providing a collection of unexplained tricks for solving specific equations. Thus, there are plenty of examples and figures, but no complicated formulas. Arnol'd is known by mathematicians and students both for his mathematical skills and for his talent for mathematical writing.