These small things - nutrition, place, climate, recreation, the whole casuistry of selfishness - are inconceivably more important than everything one has taken to be important so far.

Conversation with a friend will only bear good fruit of knowledge when both think only of the matter under consideration and forget that they are friends.

Even today a crude sort of persecution is all that is required to create an honorable name for any sect, no matter how indifferent in itself.

Linguistic danger to spiritual freedom.- Every word is a prejudice.

One never perishes through anybody but oneself.

Those who are devoid of purpose will make the void their purpose.

Metaphysical world.- It is true, there could be a metaphysical world; the absolute possibility of it is hardly to be disputed. We behold all things through the human head and cannot cut off this head; while the question nonetheless remains what of the world would still be there if one had cut it off.