"Every relationship between persons causes a picture of each to take form in the mind of the other, and this picture evidently is in reciprocal relationship with that personal relationship."
"Life cannot subsist in society but by reciprocal concessions."
"Insofar as international law is observed, it provides us with stability and order and with a means of predicting the behavior of those with whom we have reciprocal legal obligations."
"The inventions and the great discoveries have opened up whole continents to reciprocal communication and interchange, provided we are willing."
"The hypothesis may be put forward, to be tested by the s subsequent investigation, that this development has been in large part a matter of the reciprocal interaction of new factual insights and knowledge on the one hand with changes in the theoretical system on the other."