The concept of necessity — in the sense of the absolutely necessary — is to be compared with its opposite, that of contingence. For further discussion of the historical and present-day problem, the article on Absolute and Contingent should be consulted.

In this sense, the necessary transcends the opposition between freedom of choice and the determinism of physical necessity (either from without or from internal instinctive compulsions). It represents the supreme degree of the essential nec…