Farewell to the Phlogiston Theory of Conditionals

The search for a deep understanding of conditionals would go better if the taxonomy were got right first. It seems to most workers in the field that conditionals fall into two big species; and so they do. But the line between them has been drawn by everyone (including myself) in the wrong place. We have all been right in thinking that one species is typified by 'If Booth hadn't killed Lincoln, someone else would have', and the other by 'If Booth didn't kill Lincoln, someone else did'; but we have coclassified with the latter of these a kind of conditional that ought to be grouped with the former. This has led us away from important truths into quagmires and blind-alleys. It is as though anatomists were still looking for gills in whales, having classified them as fish because they live in the sea. In a way, that analogy flatters theorists of conditionals. It involves a misclassification that is based on something clear and definite (they live in the sea), whereas the wrong division through conditionals is based on virtually nothing. It hag consisted in an agreement about where the line falls, together with a hazy idea that that placing of it is supported by the conventional labels for the two species. But these labels are absurd, as I shall now show.1