(also called End, Finality, and Teleology).— An end, goal, or purpose. The final cause is that for the sake of which something either exists or is done. The final cause is the determinate thing to which an efficient cause (an agent) tends precisely as an efficient cause.  For this reason, the final cause specifies the agency of efficient causality.  (Each exercises reciprocal causality on each other, according to the maxim “causes are causes of each other,” causae ad invicem sunt causae.)  An extrinsic final cause refers to another substance for which one thing is produced (e.g., the human person is the final cause of a loaf of bread as food). An intrinsic final cause refers to the complete realization of a substance or of a process (e.g., the successfully baked loaf of bread). The final cause is first in the order of intention (as the tendency in an efficient cause) but last in the order of execution (the last thing to be achieved in a causal series).