Reasons, like science, grow by way of mutual criticism; the only possible way of ‘planning’ its growth is to develop those institutions that safeguard the freedom of this criticism, that is to say, the freedom of thought. (Popper 1950: 412)
…rationalism is linked up with the recognition of the necessity of social institutions to protect freedom of criticism, freedom of thought, and thus the freedom of men. (Popper 1950: 423)
By appealing to above sentences, Popper asserts that, growth in reason and rationalism can only be pursued in an open and liberal atmosphere. Popper believes that reason is a product of social life. We learn to argue rationally from our communication with other members of the society (Popper 1950: 411). This belief gives rise to the notion that scientific attitude is born from the society, or more precisely, from the intercourse with other human beings.
In general, open society generated by elements of individualism, equalitarianism, faith in reason, liberalism etc. encourages rational criticism. Without critical rationalism, falsification of hypotheses both in science and other human knowledge can never take place.
--- I admire Sir Karl Popper, for his wisdom, diligence and creativity. Sentences above are taken from one of my assignments in school.