The present lecture engages a speculative reading of “The Masters”, a science-fiction novel written by Ursula K. Le Guin to narrate a state where citizens are governed by the law of negating mathematics education. In this oppressive context, Le Guin crafts a collective whose desire to practice mathematics subverts the fear for death used as punishment for mathematical heresy. This allows to ponder into thinking as “negation” and “affirmation” and, consequently, to speculate two interweaved assemblages of mathematics education; first, the assemblage where negating mathematics enforces masculine knowledge enclosures and second, the assemblage of affirming the practice of mathematics as knowledge commons. The chapter contributes by rethinking of mathematics education as/for/with the commons and by discussing about speculation as an act of thinking.