心理活动是有机体与其环境的对话。
Mental activity is the organism's dialogue with its environment.
Concerning the gods, I have no means of knowing whether they exist or not or of what sort they may be. Many things prevent knowledge including the obscurity of the subject and the brevity of human life.
真正的艺术家并不骄傲：他知道艺术是无限的，他觉得自己离目标还很远。
实现明天的唯一限制是我们今天的疑虑。