EPISTEMIC MODALITY AND DEONTIC MODALITY: TWO SIDES OF A COIN
Epistemic modality refers to the use of modality which is based on the speaker's evaluation and judgment in relation to the degree of confidence of the knowledge on the proposition. It functions to comment on and evaluate an interpretation of reality in carrying out speech functions. Deontic modality indicates whether the proposition expressed by a command is obligatory, advisable or permissible according to some normative background such as law, morality, convention, etc. In many instances, the meanings of both types of modality are relative and complements to each other. The evidence of some extrinsic modalities such as must, should, may, and can indicates that they may fall under both types; thus, they are like two sides of a coin which carry its value from the meaning conveyed by each side.