Scientists are like architects who build buildings of different sizes and different shapes and who can be judged only after the event, i.e. only after they have finished their structure. It may stand up, it may fall down – nobody knows. 
Category: Against Method
An account and a truly humanitarian defence of this position [“The separation between the history of a science, its philosophy and the science itself dissolves into thin air and so does the separation between science and non-science”] can be found in J.S. Mill’s On Liberty. Popper’s philosophy, which some people would like to lay on us as the one and only humanitarian rationalism in existence today, is but a pale reflection of Mill. It is specialized, formalistic and elitist, and devoid of the concern for individual happiness that is such a characteristic feature of Mill. We can understand its peculiarities when we consider (a) the background oflogical positivism, which plays an important role in the Logic of Scientific Discovery, (b) the unrelenting puritanism of its author (and of most of his followers), and when we remember the influence of Harriet Taylor on Mill’s life and on his philosophy. There is no Harriet Taylor in Popper’s life.