A more thorough explanation:

DE ESSENTIA

De essentia means "of the essence" or "essential" in Law Latin.

It refers to something that is crucial or necessary for a particular situation or thing.

• The de essentia elements of a contract are the essential terms that must be included for the contract to be valid.
• In medicine, de essentia refers to the essential nature of a disease or condition.

These examples illustrate how de essentia is used to describe something that is fundamental or necessary. In the context of a contract, the de essentia elements are the key terms that must be present for the contract to be legally binding. In medicine, understanding the de essentia of a disease or condition is crucial for proper diagnosis and treatment.