最危险的事情就是满足于过去的成功。
The most dangerous thing is to become complacent with past success.
The environment is not a mosaic of stimuli, but a field of forces in which every part is dynamically related to every other part.
Educate the children, and it won't be necessary to punish men.
It's on the strength of observation and reflection that one finds a way. So we must dig and delve unceasingly.