Main themes and objectives of the book: a. An examination of the major flaws in the workings of today's democracies (pars destruens). b. A proposal for a renewed institutional framework (pars construens). The realization of the values and the implementation of the objectives which are indicated in democratic constitutions (political, social rights and the people's welfare) are too frequently hindered by structural defects of the legislative/government architecture and processes. This is mostly due to the inevitably "Schumpeterian" mindset and behaviour of politicians, who are more interested in gaining, maintaining, and expanding their power than in pursuing democratic/constitutional aims. Consequently, expertise and science (in the broader sense, comprising social sciences) have scarce say in politics and policy. I outline a way to insert public scientists into the core of the legislative/executive mechanisms, overcoming the ineffectual "Science speaks to power" paradigm and allowing laws, regulations and governmental actions to be more evidence-informed and constitutionally sound. In parallel, I call for a better involvement of the citizens and societal groups in the proposal, adoption and possible rejection of laws. The book is published in the website of the Bollettino telematico di filosofia politica – Overlay Journal of Political Philosophy at https://commentbfp.sp.unipi.it/giovanni-molteni-tagliabue-rationalized-and-extended-democracy-inserting-public-scientists-into-the-legislative-executive-framework-reinforcing-citizens-participation/. It is open for criticisms and suggestions by voluntary reviewers: comments may be inserted through the procedure described at https://commentbfp.sp.unipi.it/ (the instructions in English are at the bottom of the page). Comments may be “granular”: a reviewer may comment the whole book by inserting notes at the beginning ("whole page"), but notes can be related also (or only) to single chapters and sub-chapters, wherever a “comment” tag is present.