All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason. – Immanuel Kant
Experience without theory is blind, but theory without experience is mere intellectual play. – Immanuel Kant
All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope? – Immanuel Kant
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. – Talcott Parsons