Hub and Vital principle

Hub noun - A thing or place that is of greatest importance to an activity or interest.

Vital principle and hub are semantically related In some cases you can use "Vital principle" instead a noun "Hub".

Vital principle noun - A hypothetical force to which the functions and qualities peculiar to living things are sometimes ascribed.

Hub and vital principle are semantically related in center of activity topic. Sometimes you can use "Hub" instead a noun phrase "Vital principle".