In this work I argue that the lack of training in analytical and critical thinking imposes important constrains on students' understanding of academic written material, as well as on the quality of their writing. I claim that the body of cognitive tasks that pupils are asked to perform in school constitutes a profession--"pupilcy". Some examples for pupilcy are: distinguishing between different types of knowledge claims (empirical, formal, moral), choosing an appropriate procedure for assessing each such claim, assessing the credibility of a given claim, evaluating the strength of an argument, and constructing good arguments. I propose to make a course on how to teach pupilcy a mandatory component in every future teacher's training, claiming that it is in philosophy (basic epistemology and logic) rather than psychology where pupilcy should be looked for. I analyze some existing tools that attempt to improve students' analytical and critical thinking skills, and suggest tentative design principles for tools that can help teach thinking to students. Lastly, I introduce some computer-based visual tools that I have developed, which, I argue satisfy the design principles proposed above. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]