This article starts with a comment on John White's article published in 2019 in the "London Review of Education," 17 (3), entitled 'The end of powerful knowledge?', and particularly on the point made about specialized knowledge and its relation to powerful knowledge. It is argued here that it is important to clarify the distinction between specialized knowledge, systematic knowledge, and what Young and Muller mean by powerful knowledge, as, while these are related, they are not equivalent. Not all specialized knowledge is codified and systematized, and not all systematic specialized knowledge is necessarily powerful. It is suggested that some of the characteristics attributed to powerful knowledge by Young and Muller, in particular 'systematic revisability' and its enactment in specialized communities, are crucial for understanding what they mean by powerful knowledge.