infinite regress

from the GNU version of the Collaborative International Dictionary of English.

• noun (Philosophy, Logic) A causal relationship transmitted through an indefinite number of terms in a series, with no term that begins the causal chain.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun logic A regress into an infinite sequence of propositions in an attempt to found the truth of the proposition Pi on the truth of the proposition Pi+1.