In Section 2 of the prologue to Jami's Leyli va Majnoon (within the Haft Awrang), discursive thought (fikr) is cast upon the chain of contingent beings (silsila-yi mumkinat): every effect (athar) is traced back to its producing cause (mu'aththir). Although reality branches into countless causal chains, all of them terminate at a single point — the Necessary Being (wajib al-wujud) — just as every radius issues from the one center of a circle. This distills the classical proof from contingency: contingent things do not exist through themselves, an infinite regress of causes (tasalsul) is impossible, and reason is therefore compelled to ascend to the Unity (tawhid) of the single self-subsistent Cause.