If it is true that the mind extends out into the word, then we should expect to find some mind-like artifacts in the world. In keeping with this, some philosophers have suggested that images can be arguments. I have explored the cognitive contribution of diagrams like timelines in historical inquiry. Images like these obviously lend support to individual premises. However, I argue that the static nature of images prevents them from ever playing a genuinely argumentative role. To show this, I propose a dilemma. If visual arguments include their conclusion, then they risk begging the question. If visual arguments do not include their conclusion, then the content of an image must license only a subset of possible conclusions, in accordance with some principled rationale. The examples presented in the argumentation theory literature fail to escape this dilemma. Even so, I use the Existential Graphs of C. S. Peirce to show how images can be manipulated (erased, moved, increased, etc.) in a way that enables some form of visual reasoning. Static picturing of states of affairs may, as Wittgenstein claimed, be a good way to describe the epistemic work done by propositions. Yet, if consciousness is an ever-moving stream and if arguments are nothing more than segments of that stream, then arguments must be processual too. I have presented this argument at the 2018 meeting of the Canadian Philosophical Association (in Montreal, June 4–7).
Conscious experience involves many senses, so a related question I am investigating is whether non-visual diagrams are possible. In a 2015 Logica Universalis piece, I demonstrated that, while there are lingering difficulties with double-negation, the project of an “acoustic logic” is feasible. People at the non-profit organization METI International (“Messaging to Extra-Terrestrial Intelligence”) have shown an interest in that work. METI ventures gain considerable motivation from recent planetary science. The more exoplanets we find, the more likely it is that “exominds” await our messages. METI researchers thus seek to determine the optimum structure of their interstellar messages. Yet, there are presently no well-confirmed tests against which to check the design of such messages. In the meantime, the best we can do is distance ourselves from “terracentric” assumptions. There is no reason, for instance, to assume that all thinking is language-like.
My academic background puts me in an ideal position to contribute to these debates. Not only do I have a PhD in philosophy of signs, I have PhD in philosophy of mind. We speak of “philosophy of mind” and not “philosophy of the mind” so as to not prejudge which mind we are talking about. METI research lets this broad view have a tangible application. Pursuant with this, I argue that logical inferences do not have to happen in a symbolic format. Since diagrams are less dependent on convention and might even be generalized to cover non-visual senses, I argue that METI researchers should add some form of diagrammatic reasoning to their repertoire. I have presented a paper on this at the Canadian Society for the History and Philosophy of Science, which has since been reworked into a full article, now accepted at Studies in History and Philosophy of Science.
In addition to its sheer interest, I surmise that a diagrammatic approach to logic can connect better with students who recoil from regular symbolic notations. I suspect that this is the case, because I recently taught argument diagramming to a student who is blind, using a gestural and bodily technique that I designed. I have shared these results at the 10th International Conference on the Theory and Application of Diagrams (in Edinburgh, Scotland, June 18–22), the proceedings of which have since been published by Springer. High-level research is even better when it makes a positive difference in people’s lives, so I will continue exploring these exciting applications in the next years.