To a constant practitioner

Meaning

Phrase.

The dative phrase completes Mercury’s claim that he is constant. Its parallel, fixed to a steadfast mind, turns the accusation of material inconstancy back upon the operator who moves from one matter to another. The passage does not abolish volatility; it joins a technical contrast to a test of the person interpreting it. The constancy claimed is relational, not an unqualified denial of movement.