I know that the most joy in my life has come to me from my violin.

It must be conceded that a theory has an important advantage if its basic concepts and fundamental hypotheses are 'close to experience,' and greater confidence in such a theory is certainly justified. There is less danger of going completely astray, particularly since it takes so much less time and effort to disprove such theories by experience. Yet more and more, as the depth of our knowledge increases, we must give up this advantage in our quest for logical simplicity in the foundations of physical theory.

Our separation from each other is an optical illusion.

Out of the multitude of our sense experiences we take, mentally and arbitrarily, certain repeatedly occurring complexes of sense impression (partly in conjunction with sense impressions which are interpreted as signs for sense experiences of others), and we attribute to them a meaning the meaning of the bodily object.

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

Condemnation before investigation is the highest form of ignorance.

I regard class differences as contrary to justice and, in the last resort, based on force.