Sentence:  I also saw, or thought I saw, a very similar clash of assumptions, hypotheses and  explanatory styles between the tenets of the old orthodoxy (a mixture of  behaviourism, structuralism, cultural relativism, Wittgensteinian holism and Piagetian constructivism) and the ideas of the new <WSD>trenders</WSD>. 
Meaning of the word marked with <WSD> tags:  Someone who is trendy, who sets or follows trends.