preceptive

precept +‎ -ive

preceptive (comparative more preceptive, superlative most preceptive)

1. (law) Of, pertaining to, or based on precepts
   • 1677, John Owen, The Doctrine of Justification by Faith‎:

     If it was necessary, that Christ as our surety should suffer the penalty of the law in our stead, because we have sinned; then it was also necessary that as our Surety, he should yield obedience to the preceptive part of the law also;

2. instructive; didactic
   • 1810, John Quincy Adams, Lectures on Rhetoric and Oratory‎:

     It is altogether preceptive, barely containing the rules, without illustration from example. It is a system of rhetoric in the abstract.

• perceptive