Toynbee presents contact between civilisations as one of the fundamental forces shaping human history. Societies do not develop in isolation: encounters with different peoples, institutions, beliefs and technologies can introduce new possibilities, provoke resistance or expose existing weaknesses. For Toynbee, such contact can therefore contribute both to advancement and to breakdown.

The statement is deliberately general. Toynbee treats interaction between civilisations not as a feature of one historical period but as a recurring and continuing influence on human development. The word “ruling” indicates the importance he assigns to this process within his understanding of history. Contact itself is neither inherently beneficial nor destructive; its consequences depend on the circumstances of the encounter and the responses of the societies involved. The quotation expresses a central feature of Toynbee’s historical outlook: civilisations are shaped substantially through their relationships with one another.