 Fourth, Herder holds that aesthetic values such as beauty are fundamentally a matter of feelings and that the feelings in question vary in important ways between one period, culture, or even individual and another. This theme is already prominent in On the Ode, where he discusses major differences in the feelings of beauty that occur between different periods/cultures—for example, between his own age and the age of the ancient Greeks. It is also prominent in On the Change of Taste (1766), where he adds that the changes involved are indeed sometimes extreme enough to amount to an outright inversion.