In this article we address a hitherto unstudied causal conjunction in English, seeing as though. Occurring predominantly in informal registers, the conjunction is typically used to introduce information which the speaker takes to be self-evidently true and on whose basis some further comment, or query, is made. Drawing on data derived from internet searches we draw up a semantic profile of the expression in comparison and contrast with other reason connectives, namely, seeing (that) and since. The data suggest that seeing as though is associated with highly subjective construals of the reason relation. We also address the internal structure of the expression. The use of seeing in a reason conjunction is traced to a common conceptual metaphor, whereby knowing is seeing. More puzzling is the occurrence of as though. While rejecting the possibility of a compositional analysis of the expression, we note that as though is only one of a number of items which can occur with causal seeing. These items have to do with the appearance of things and are in fact able to occur as complementizers after predicates of seeming and appearing. To this extent, as though is consistent with the subjectivity associated with the complex conjunction. In the course of our investigation, we also document the extraordinary proliferation of reason connectives that involve lexical items such as seeing, as, though, and several others, and suggest that this exuberance of new forms may not be unrelated to the subjectivity inherent in the construal of causal relations.