The series of integers is obviously an invention of the human mind, a self-created tool which simplifies the ordering of certain sensory experiences.
Albert EinsteinStudent: Dr. Einstein, Aren't these the same questions as last year's [physics] final exam? Dr. Einstein: Yes; But this year the answers are different.
Albert EinsteinFrom the standpoint of daily life, however, there is one thing we do know: that we are here for the sake of each other - above all for those upon whose smile and well-being our own happiness depends, and also for the countless unknown souls with whose fate we are connected by a bond of sympathy. Many times a day I realize how much my own outer and inner life is built upon the labors of my fellow men, both living and dead, and how earnestly I must exert myself in order to give in return as much as I have received.
Albert Einstein