"With adequate safeguards and cautious preparation, genetic engineering could be used to relieve suffering and increase happiness by quantum leaps. Our short-term prospect here would be the eradication of many genetic handicaps. The medium-term prospect could be the reduction of the proportion of the neurotic and depressed personality. The longer-term prospect might be the dramatic enhancement of our capacity for enjoyment. All these have to be done with extreme caution. The reason we should be very cautious is not so much to avoid sacrificing our current welfare (which is relative small in comparison to that in the future with brain stimulation and genetic engineering) but to avoid destroying our future."