The idea of using pleasure or bliss, unified with emptiness, for example the use of sex in tantras is because of the immediate presence discovered in such a state. It has become almost a cliché in western thought that the moment of sexual climax is one where the person is not lost in daydreams but rather is fully present.
So, Nydahl might use this language, but to place it in context, this is
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"Cults," Sects, and "New Religious Movements"