He who joyfully marches to music in rank and file has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would suffice.

The whole of science is nothing more than a refinement of everyday thinking.

Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.

The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.

Paper is to write things down that we need to remember. Our brains are used to think.

Few people think more than two or three times a year; I have made an international reputation for myself by thinking once or twice a week.