Henry Cloud and John Townsend open Boundaries with their foundational premise: healthy personal boundaries — clear definitions of where one person's responsibility ends and another's begins — are essential for genuine psychological health and healthy relationships, and their absence reliably produces resentment, burnout, and dysfunctional relational patterns.

Cloud and Townsend's foundational argument:

• They draw on both psychological principles and their explicitly stated Christian faith perspective to argue that clear boundaries — knowing and communicating what one is and isn't responsible for within a relationship — represent a foundational, biblically-grounded psychological health principle, rather than a purely secular psychological technique
• The authors argue that boundary absence, frequently rooted in specific family-of-origin patterns or religious misunderstanding equating boundary-setting with selfishness, produces a pattern of chronic over-functioning and resentment that ultimately damages both the over-functioning individual and their relationships
• This foundational framing sets up the book's overall project: addressing common boundary myths and misconceptions, examining boundary development across the lifespan, and providing specific practical guidance for establishing healthy boundaries across distinct relationship contexts

This foundational premise establishes the book's distinctive approach, combining psychological principle with explicit Christian theological grounding, distinguishing it from more purely secular psychological treatments of similar boundary-setting concepts.