I've just finished and greatly enjoyed reading Greg Bear's EON which includes:
There are an infinite number of alternatives to the Way, each originating in an alternative world-line, yet reaching beyond that world-line. Until now, Way researchers have not known quite how the alternate Ways were stacked or arranged, or indeed whether they could even be considered real. Since the Way intersects a large number of alternative world-lines - perhaps all - could there be more than one Way?
The variety of emotions available to a reconfigured human mind, thinking thoughts impossible to its ancestors . . .
The emotion of -*-, describable only as something between sexual love and the joy of intellection - making love to a thought? Or &&, the true reverse of pain, not "pleasure" but a "warning" of healing, growth and change. Or (^+^), the most complex emotion yet discovered, felt by those who consciously endure the change between mind configurations, and experience the broad spectrum of possibilities inherent in thinking and being.
pp. 492-493. Gollancz, paperback, 1985.
According to the cover I note that Mr Bear is married to the daughter of Poul Anderson an author who also figures in my (dated!) collection. A favourite is Tau Zero which I also recently re-read and passed-on. As to the quotes above I will let them stand for themselves. ...