When Bastian finally published his studies and observations as Journey through Cambodia to Cochinchina in Germany in 1868 - told in detail but uninspiredly, above all without a single one of his drawings - this work did not became influential, though at about the same great popularity was accrued by Henri Mouhot's posthumous work with vivid descriptions of Angkor, Travels in the Central Parts of Indo-China, Siam, Cambodia and Laos, published in 1864 through the Royal Geographical Society.

He also worked with Rudolf Virchow to organize the Berlin Society for Anthropology, Ethnology, and Prehistory, which would use the ZfE as its main publication outlet.

Bastian is remembered as one of the pioneers of the concept of the 'psychic unity of mankind' – the idea that all humans share a basic mental framework.

While Bastian considered himself to be extremely scientific, it is worth noting that he shared the naturalist tradition that was inspired by Johann Gottfried Herder and exemplified by people such as Alexander von Humboldt.

As a result, he remained hostile to Darwin's theory of evolution (and its main German advocate, Ernst Haeckel), because the physical transformation of species had never been observed empirically, despite the fact that he posited a similar evolutionary development for human civilization.

[citation needed] In arguing for a "psychic unity of mankind," Bastian proposed a straightforward project for the long-term development of a science of human culture and consciousness.

Bastian also proposed a "genetic principle" by which societies develop during the course of their history from exhibiting simple sociocultural institutions to becoming increasingly complex in their organization.

Through the accumulation of ethnographic data, we can study the psychological principles of mental development as they reveal themselves in diverse regions and subject to differing conditions.

Because one cannot observe the collective representations per se, Bastian claimed that the ethnographic project had to proceed through a series of five analytical steps (see Koepping, 1983):