[The child] takes his play very seriously and he expends large amounts of emotion on it. The opposite of play is not what is serious but what is real.

Religious illusion must bow to scientific truth. It is in total error about the nature of the true world. Only science is not an illusion.

We are what we are because we have been what we have been.

Our possibilities of happiness are already restricted by our constitution. Unhappiness is much less difficult to experience. We are threatened with suffering from three directions: from our own body, which is doomed to decay and dissolution and which cannot even do without pain and anxiety as warning signals; from the external world, which may rage against us with overwhelming and merciless forces of destruction; and finally from our relations to other men. The suffering which comes from this last source is perhaps more painful to us than any other.

We are so constituted that we can gain intense pleasure only from the contrast, and only very little from the condition itself.

Religious doctrines … are all illusions, they do not admit of proof, and no one can be compelled to consider them as true or to believe in them.

Creativity is an attempt to resolve a conflict generated by unexpressed biological impulses, such that unfulfilled desires are the driving force of the imagination, and they fuel our dreams and daydreams.