We humans are an extremely important manifestation of the replication bomb, because it is through us - through our brains, our symbolic culture and our technology - that the explosion may proceed to the next stage and reverberate through deep space.
One of the things I have tried to do with this book and with all of them really is avoid that simple, easy, reductionist view of motivation and to show we do things for a complex net of reasons, a real braid of reasons.