The same phenomenon is observed in the case of moral characteristics. Alongside the unalterable psychological elements of a race, mobile and changeable elements are to be encountered. For this reason, in studying the beliefs and opinions of a people, the presence is always detected of a fixed groundwork on which are engrafted opinions as changing as the surface sand on a rock.
The opinions and beliefs of crowds may be divided,then, into two very distinct classes. On the one hand we have great permanent beliefs, which endure for several centuries, and on which an entire civilisation may rest. Such, for instance, in the past were feudalism,Christianity, and Protestantism; and such, in our own time, are the nationalist principle and contemporary democratic and social ideas. In the second place, there are the transitory, changing opinions, the outcome,as a rule, of general conceptions, of which every age sees the birth and disappearance; examples in point are the theories which mould literature and the arts—those, for instance, which produced romanticism,naturalism, mysticism, &c. Opinions of this order are as superficial, as a rule, as fashion, and as changeable.They may be compared to the ripples which ceaselessly arise and vanish on the surface of a deep lake.