5. Morphology in Relation to Phonology

F. Plank, Morphology I: 5. Morphology in Relation to Phonology 2
5.1. Morphology before phonology, step-by-step, hand-in-hand
Morphology is responsible (in cooperation with the lexicon and syntax)
for the expression of meanings. For their distinctive expression:
linguistic structures are systems of contrasts (e.g., PLURAL means
something different when part of a two-way or of a three-way system of
NUMBER contrasts, SG - PL or SG - DU - PL).
What phonology is responsible for is that these meanings, as expressible
and distinguishable courtesy of the lexicon (= basic units) and of
morphology and syntax (= constructions) are (i) (easily) pronounceable
and (ii) (easily) perceivable.
It follows from this division of labour that morphology ought to have
priority over phonology: first morphology (with lexicon and syntax)
needs to provide forms-in-constructions, then phonology can see to it
that they are (easily) pronounceable and perceivable.