Journal for the History of Analytical Philosophy <p>JHAP aims to promote research in and discussion of the history of analytical philosophy. <a href="/jhap/about">Read more ...</a></p> McMaster University en-US Journal for the History of Analytical Philosophy 2159-0303 <p>The Public Knowledge Project recommends the use of the Creative Commons license. The Journal for the History of Analytical Philosophy requires authors to agree to a <a href="">Creative Commons Attribution /Non-commercial license</a>. Authors who publish with the Journal for the History of Analytical Philosophy agree to the following terms:</p><ol><li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <a href="">Creative Commons BY-NC license</a>.</li><li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li><li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access)</li></ol><p><a href="" rel="license"><img style="border-width: 0;" src="" alt="Creative Commons License" /></a><br />This work is licensed under a <a href="" rel="license">Creative Commons Attribution-NonCommercial 3.0 Unported License</a>.</p> On the Curious Calculi of Wittgenstein and Spencer Brown <p>In his <em>Tractatus</em>, Wittgenstein sets out what he calls his N-operator notation which can be used to calculate whether an expression is a tautology. In his <em>Laws of Form</em>, George Spencer Brown offers what he calls a “primary algebra” for such calculation. Both systems are perplexing. But comparing two blurry images can reduce noise, producing a focus. This paper reveals that Spencer Brown independently rediscovered the quantifier-free part of the N-operator calculus. The comparison sheds a flood light on each and from the letters of correspondence we shall find that Russell, as one might have surmised, was a catalyst for both.</p> Gregory Landini ##submission.copyrightStatement## 2018-12-09 2018-12-09 6 10 10.15173/jhap.v6i10.3400