Elements essential to existence of a contract are:

1. (1) Parties capable of contracting;
2. (2) Their consent;
3. (3) A lawful object; and
4. (4) Sufficient cause or consideration.

Source: CivC 1877, § 871; CL 1887, § 3495; RCivC 1903, § 1189; RC 1919, § 804; SDC 1939, § 10.0102.