Which is not an essential characteristic of any contract, including an insurance contract?

In the context of contracts, including insurance contracts, essential characteristics generally include competent parties, consideration, and a legal purpose. Competent parties refers to the requirement that individuals involved have the legal capacity to enter into a contract. Consideration is something of value exchanged between the parties, and legal purpose means that the contract must be for a lawful objective.

Concatenation, however, is not a recognized essential characteristic of contracts. The term typically relates to linking or chaining things together, and while it might have relevance in other fields, it does not pertain to the foundational elements required for a valid contract in insurance or any other context. This distinguishes it from the fundamental requirements that must always be present for a contract to be enforceable.