"Common to all these types is the anthropomorphic character of the idea of God. Only exceptionally gifted individuals or especially noble communities rise essentially above this level; in these there is found a third level of religious experience, even if it is seldom found in a pure form. I will call it the cosmic religious sense. This is hard to make clear to those who do not experience it, since it does not involve an anthropomorphic idea of God; the individual feels the vanity of human desires and aims, and the nobility and marvelous order which are revealed in nature and in the world of thought. He feels the individual destiny as an imprisonment and seeks to experience the totality of existence as a unity full of significance. Indications of this cosmic religious sense can be found even on earlier levels of development—for example, in the Psalms of David and in the Prophets. The cosmic element is much stronger in Buddhism, as, in particular, Schopenhauer's magnificent essays have shown us. The religious geniuses of all times have been distinguished by this cosmic religious sense, which recognizes neither dogmas nor God made in man's image. Consequently there cannot be a church whose chief doctrines are based on the cosmic religious experience. It comes about, therefore, that we find precisely among the heretics of all ages men who were inspired by this highest religious experience; often they appeared to their contemporaries as atheists, but sometimes also as saints. Viewed from this angle, men like Democritus, Francis of Assisi, and Spinoza are near to one another."

“Everything should be made as simple as possible, but not simpler.”

“The most simple picture one can form about the creation of an empirical science is along the lines of an inductive method. Individual facts are selected and grouped together such that their lawful connection becomes clearly apparent. ... The truly great advances in our understanding of nature originated in a manner almost diametrically opposed to induction. The intuitive grasp of the essentials or a large complex of facts leads the scientist to the postulation of a hypothetical basic law, or several such basic laws. From the basic laws (system of axioms) he derives his conclusions as completely as possible in a purely logically deductive manner. These conclusions, derived from the basic laws (and often only after time-consuming developments and calculations), can then be compared to experience, and in this manner provide criteria for the justification of the assumed basic law.”

“Noch eine Art Anwendung des Relativitätsprinzips zum Ergötzen des Lesers: Heute werde ich in Deutschland als "deutscher Gelehrter", in England als "Schweizer Jude" bezeichnet; sollte ich aber einst in die Lage kommen, als "bète noire" präsentiert zu werden, dann wäre ich umgekehrt für die Deutschen ein „Schweizer Jude", für die Engländer ein "deutscher Gelehrter".”

“Liebe Mutter! Heute eine freudige Nachricht. H. A. Lorentz hat mir telegraphiert, dass die englischen Expeditionen die Lichtablenkung an der Sonne wirklich bewiesen haben.”

“"The physical world is real." That is supposed to be the fundamental hypothesis. What does "hypothesis" mean here? For me, a hypothesis is a statement, whose truth must be assumed for the moment, but whose meaning must be raised above all ambiguity. The above statement appears to me, however, to be, in itself, meaningless, as if one said: "The physical world is cock-a-doodle-do." It appears to me that the "real" is an intrinsically empty, meaningless category (pigeon hole), whose monstrous importance lies only in the fact that I can do certain things in it and not certain others.”

“Geh Recht viel spazieren, dass Du Recht gesund wirst und lies nicht gar zu viel sondern spar Dir noch was auf bis Du gross bist.”