The material which a scientist actually has at his disposal, his laws, his experimental results, his mathematical techniques, his epistemological prejudices, his attitude towards the absurd consequences of the theories which he accepts, is indeterminate in many ways, ambiguous, and never fully separated from the historical background . This material is always contaminated by principles which he does not know and which, if known, would be extremely hard to test.
Paul FeyerabendConfronted with such a variety most philosophers try to establish one approach to the exclusion of all others. As far as they are concerned there can only be one true way- and they want to find it. Thus normative philosophers argue that knowledge is a result of the application of certain rules, they propose rules which in their opinion constitute knowledge and reject what clashes with them.
Paul FeyerabendI had studied Dadaism after the Second World War. What attracted me to this movement was the style its inventors used when not engaged in Dadaistic activities. It was clear, luminous, simple without being banal, precise without being narrow; it was a style adapted to the expression of thought as well as of emotion. I connected this style with the Dadaistic exercises themselves
Paul FeyerabendSo far Unitarian realism claiming to possess positive knowledge about Ultimate Reality has succeeded only by excluding large areas of phenomena or by declaring, without proof, that they could be reduced to basic theory, which, in this connection, means elementary particle physics.
Paul FeyerabendGiven any rule, however "fundamental" or "necessary" for science, there are always circumstances when it is advisable not only to ignore the rule, but to adopt its opposite. For example, there are circumstances when it is advisable to introduce, elaborate and defend ad hoc hypotheses, or hypotheses which contradict well-established and generally accepted experimental results, or hypotheses whose content is smaller than the content of the existing and empirically adequate alternative, or self-inconsistent hypotheses, and so on.
Paul Feyerabend