Defense
The child cannot try to defend against his experience in the
present moment and at the same time remain in touch with his present
essential nature. Thus, all ego defenses, necessary though they
are for the psychological balance of the inadequately cared-for
child, contribute to his disconnection from his essential core,
and thus to his narcissism… Not only defenses, but many
kinds of structures develop in defensive ways. Some ego structures
actually develop specifically for defense, for example, those
which constitute the schizoid character. In attempting to avoid
dealing with very painful object relations the child defends by
isolating himself from his felt experience in general. This defensive
detachment isolates him not only from his emotions, but also from
his essential Presence, characterized by vivid affects and qualities
of aliveness. If he were in touch with the essential Presence,
he would lose his capacity to isolate himself from his emotions,
because the Presence would open him to his present experience,
whatever its content. (The Point of Existence, pg 187)

Defense and Being
From our perspective, however, just as it is known in psychoanalysis
that some identification systems are defenses against other systems,
or against id impulses, they (all identification systems) are
usually defenses against the various aspects of Being. Being is
always there; it is what we are in the most fundamental way. That
it is not in conscious experience indicates the presence of defenses
against it; it becomes part of the content of the unconscious.
And any identification system taken to give the individual a sense
of self or individuality is bound to function as a defense against
Being because Being is who one is, it is the true self. (The Pearl
Beyond Price, pg 138)

Defense and negative merging
The first defensive operations are those of splitting and projection.
The negative merging is split off, seen as separate and unrelated
to the positive merging, and projected outside; thus it is perceived
as part of the environment. (The Pearl Beyond Price, pg 246)

Defense and personality
The moment you become aware of the vicious cycle of the activity
of defensiveness, you will see clearly that what you have been
rejecting is yourself, and that the rejection is useless and unnecessary.
Then you will relax and stop. The complete perception of this
cycle is the stopping of the wheels. Then the personality is dissolved
by clarity. There is clarity because there is no movement in the
personality separating it from Being. (Diamond Heart Book 4, pg
12)

Defense and Will
The moment one identifies with a defensive structure one cuts
himself off from the Will of Essence. Understanding this can bring
a precise understanding of the difference between the beingness
of Being and the activity of ego. Castration anxiety is a direct
consequence of being cut off from the Will Essence. The Oedipal
situation augments the situation, but does not create it. (The
Pearl Beyond Price, pg 301)