Perichoreisis

[Byzantine]

I'm reading a work by a Melkite archbishop and the term came up. What is it?

[cappie]

"The penetration and indwelling of the three divine persons reciprocally in one another. In the Greek conception of the Trinity there is an emphasis on the mutual penetration of the three persons, thus bringing out the unity of the divine essence. In the Latin idea called circumincession the stress is more on the internal processions of the three divine persons. In both traditions, however, the fundamental basis of the Trinitarian perichoresis is the one essence of the three persons in God. The term is also applied to the close union of the two natures in Christ. Although the power that unites the two natures proceeds exclusively from Christ's divinity, the result is a most intimate coalescence. The Godhead, which itself is impenetrable, penetrates the humanity, which is thereby deified without ceasing to be perfectly human. "

from Fr. John Hardon's Modern Catholic Dictionary