The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have not legitimacy.
We come now to the question: what is a priori certain or necessary, respectively in geometry (doctrine of space) or its foundations? Formerly we thought everything; nowadays we think nothing. Already the distance-concept is logically arbitrary; there need be no things that correspond to it, even approximately.
You must be aware that most men (and also not only a few women) are by nature not monogamous. This nature makes itself even more forceful when tradition and circumstance stand in an individual's way.
The most important human endeavor is the striving for morality in our actions. Our inner balance and even our very existence depend on it. Only morality in our actions can give beauty and dignity to life. To make this a living force and bring it to clear consciousness is perhaps the foremost task of education. The foundation of morality should not be made dependent on myth nor tied to any authority lest doubt about the myth or about the legitimacy of the authority imperil the foundation of sound judgment and action.
I believe, indeed, that overemphasis on the purely intellectual attitude, often directed solely to the practical and factual, in our education, has led directly to the impairment of ethical values. I am not thinking so much of the dangers with which technical progress has directly confronted mankind, as of the stifling of mutual human considerations by a 'matter-of-fact' habit of thought which has come to lie like a killing frost upon human relations. Without 'ethical culture' there is no salvation for humanity.
Epistemology without contact with science becomes an empty scheme. Science without epistemology is-insofar as it is thinkable at all-primitive and muddled.
When a man points a finger at someone else, he should remember that three of his fingers are pointing at himself. Do not worry about your difficulties in mathematics; I can assure you that mine are still greater.