The universal chain appears most prominently in Lines 83-84, where the pessimist speaker asks if the chains of fate are so strong that even God himself is bound by them. Though the concept of the universal chain only breaks through the surface of the poem once, it undergirds the pessimist’s argument because it acts as a synecdoche for God’s powers. If the chain cannot be broken, then God is not omnipotent; if the chain can be broken, then God permitted thousands of innocent people to die at Lisbon and he is therefore not benevolent. These possibilities are returned to throughout the poem, even without continued mention of the universal chain.

The chain itself is a principle of causation that Leibniz used. Effectively, it holds that the cause of each major event is contained in the preceding event, and that event’s cause is also contained in some preceding event, and so on until it reaches an action undertaken or ordained by God.

The symbol of the potter’s vessel ties in with the theme of human frailty. In a counterargument to the main speaker’s conceit that humans suffer too severely under God’s whims, the potter’s vessel is offered from Line 99 to Line 103 as an