Among the major policies that have been implemented to ensure its continued success, "Thinking Schools, Learning Nation" (TSLN) has been described as the "big bang of educational reforms" in Singapore. However, while the policy aims to develop critical thinkers in school leavers, the corporatisation of education in the shape of structures such as the school excellence model seems to be at odds with TSLN. This paper argues that these structures unwittingly engender a culture of performativity among schools, marginalising the central outcome of its initiative that entails developing a culture of thinking and thinkers. The tension is further exacerbated by the larger rationalities that have shaped Singapore and the pragmatic and instrumental philosophy which underpins its educational system. The tensions generated by the clash between intended (culture of thinking) and engendered culture (culture of performativity) present the challenge of mediation for the system on its path to realising TSLN.