It is still a rather new observation that certain states of the gene function induced by environmental changes may be inherited not only from one cell generation but also from one individual generation to the next. This is called epigenetic inheritance. Epigenetic inheritance is, in a manner of speaking, inheritance of acquired characteristics, but it is more correct to call it inheritance of acquired states. The prevailing neo-Darwinian or synthetic theory of evolution forbids the inheritance of acquired characteristics. Thus, does epigenetic inheritance revolutionize the foundations of the theory of evolution? Contrary to the common belief, Charles Darwin himself did not, however, forbid the inheritance of acquired characteristics, but considered it possible and even probable. This becomes apparent in his book The Descent of Man from 1871. According to the comprehension of the present author, epigenetic inheritance adds one more type of variation to the theory, and extends our comprehension of inheritance and adaptation. Moreover, and more importantly, it in no way alters the core of the theory of evolution, the principle of selection.