 Logic, in this framework, seeks and systematizes certain patterns in the linguistic recordings of our activities of mathematical construction. It is an application of mathematics to the language of mathematics. Specifically, logic studies the patterns that characterize valid inference. The aim is to establish general rules operating on statements about mathematical constructions such that, if the original statements (the premises) convey a mathematical truth, so will the statement obtained by applying the rule (the conclusion; Brouwer 1949C: 1243). What is preserved in an inference from given premises to a conclusion is therefore not, as in classical logic, a kind of possibly evidence-transcendent truth, but constructibility. This view is quite explicit already in Brouwer’s dissertation (Brouwer 1907: 125–132, 159–160 [1975: 72–75, 88]), but a more memorable passage is in the paper from 1908: