The more the fruits of knowledge become accessible to men, the more widespread is the decline of religious belief.

Just as a cautious businessman avoids investing all his capital in one concern, so wisdom would probably admonish us also not to anticipate all our happiness from one quarter alone.

Religion belonged to the infancy of humanity. Now that humanity had come of age, it should be left behind.

There is no likelihood of our being able to suppress humanity's aggressive tendencies... Complete suppression of man's aggressive tendencies is not an issue; what we may try is to direct it into a channel other than that of warfare.

Look into the depths of your own soul and learn first to know yourself, then you will understand why this illness was bound to come upon you and perhaps you will thenceforth avoid falling ill.

Writing was in its origin, the voice of an absent person.

The most complicated achievements of thought are possible without the assistance of consciousness.