A student gazes at a mystery solution. Its contents are unknown. The student reaches into her toolkit, a set of known solutions, and one by one, combines them with a small portion of the mystery solution. One test changes the color to bright yellow. Another produces a milky, solid substance. Gradually, the student pieces together the clues that allow her to identify the unknown solution.Too often US "reformers" believe that critical thinking like this can be taught, that repetition and practice is "Drill and Kill" and that foundation work can be ignored until the student "needs it", at which point the Omniscient Google can be used -- no need to memorize anything.
This qualitative analysis laboratory required the student to recall properties of different solutions, understand reaction processes, and synthesize the results of different experimental tests while under pressure. To practice, the student had worked together with classmates to identify a series of mystery solutions and shared their findings with their classmates.
Critical thinking requires the foundation in order to be effective. That student needed to know how chemicals react, the contents of her "toolkit" and have a basic understanding of the processes.
Prior knowledge leads to further learning. Memorized knowledge is a prerequisite for critical thinking.