Property should be in a certain sense common, but, as a general rule, private; for, when every one has a distinct interest, men will not complain of one another, and they will make more progress, because every one will be attending to his own business.
Only those young people can be accepted as healthy who refuse to be reconciled with the old order and foolishly or wisely struggle against it - such is the will of nature...
Science has given to this generation the means of unlimited disaster or of unlimited progress. There will remain the greater task of directing knowledge lastingly towards the purpose of peace and human good.