Partially initiated members buffer an inner circle from outsiders while linking them.

Evidence

The contrast between exoteric and esoteric members, such as is attributed to the Pythagorean order, is the most poignant form of this protective measure. The circle composed of those only partially initiated formed a sort of buffer region against the non-initiates. It is everywhere the dual function of the “middler” to connect and to separate, or, actually, rather to play only one role which, according to our perceptual categories and our viewpoint, we designate as connecting or as separating. — Georg Simmel, The Sociology of Georg Simmel, 8873