“What we observe is not nature itself, but nature exposed to our method of questioning.”

“What we observe is not nature itself, but nature exposed to our method of questioning.”

“We have to remember that what we observe is not nature in itself butnature exposed to our method of questioning.”

“We are by nature observers, and thereby learners. That is our permanent state.”

“It is hard to believe that this simple truth is not understood by those leaders who forbid their followers to use effective contraceptive methods. They express a preference for 'natural' methods of population limitation, and a natural method is exactly what they are going to get. It is called starvation.”

“Nature consists of facts and of regularities, and is in itself neither moral nor immoral. It is we who impose our standards upon nature, and who in this way introduce morals into the natural world, in spite the fact that we are part of this world. We are products of nature, but nature has made us together with our power of altering the world, of foreseeing and of planning for the future, and of making far-reaching decisions for which we are morally responsible. Yet, responsibility, decisions, enter the world of nature only with us”