The recent wave of data on exoplanets lends support to METI ventures (Messaging to Extra-Terrestrial Intelligence), insofar as the more exoplanets we find, the more likely it is that “exominds” await our messages. Yet, despite these astronomical advances, there are presently no well-confirmed tests against which to check the design of interstellar messages. In the meantime, the best we can do is distance ourselves from terracentric assumptions. There is no reason, for example, to assume that all inferential abilities are language-like. (...) With that in mind, I argue that logical reasoning does not have to be couched in symbolic notation. In diagrammatic reasoning, inferences are underwritten, not by rules, but by transformations of self-same qualitative signs. I use the Existential Graphs of C. S. Peirce to show this. 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 representations to their repertoire. Doing so can shed light, not just on alien minds, but on the deepest structures of reasoning itself. (shrink)

Beyond the obvious technical difficulties, human attempts to communicate with hypothetical Extra-Terrestrial Intelligences also present a number of philosophical puzzles. After all, an alien intelligence is likely the closest thing to a Wittgensteinian lion humanity could ever encounter. In this paper I advance a new challenge for the feasibility of communication with extra-terrestrials. The problem I raise is a practical problem that falls out of the history and philosophy of mathematics and the implementation of METI projects—specifically, the semiprime self-decryption schema (...) of the Drake Pictures message strategy. The Drake Pictures strategy presumes that aliens share the concept ‘prime number’ with us, as understanding that concept is necessary to decrypt our message. However, if the concept ‘prime number’ exhibited open texture at any point in its history, it could have developed in a different direction than it did in our history. If that is so, an alien could have the concept ‘prime number’ and still not be capable of decrypting our messages. I argue that this new problem is more trenchant than previous arguments in both the philosophy and SETI literature, such as applications of the aforementioned Lion argument and other concerns about the possibility of long-range communication without the assumption of shared concepts. (shrink)

My topic is extraterrestrial intelligence. Following current conventions, I use the abbreviation ‘ETI’ to stand for three related concepts: the abstract idea of extraterrestrial intelligence, individuals who are both extraterrestrial and intelligent, and the hypothesis that there are ETIs. SETI is the search for ETIs, and CETI is the attempt to communicate with ETIs. In this paper, I will try to answer the two most basic questions in extraterrestrial studies. First, what is the status of the ETI hypothesis? In the (...) light of what we know, how likely is it that there are ETIs? Secondly, what is the value of pursuing SETI? Are the expected epistemic and pragmatic payoffs sufficient to warrant an extensive search? The first, substantive question is discussed in Section 2, Section 3 and Section 4. The second, ‘program evaluation’ question is the subject of Section 5 and Section 6. But first we'll take a brief look at some of the early history of the topic. (shrink)