The Counterpossibles of Science vs. the Science of Counterpossibles

Orthodoxy has it that all counterpossibles are vacuously true. Yet there are strong argumentsboth for and against the use of non-vacuous counterpossibles in metaphysics. Even more compelling evidence may be expected from science. Arguably philosophy should defer to best scientific practice. If scientific practice comes with a commitment to non-vacuous counterpossibles, this may be the decisive reason to reject semantic orthodoxy and accept nonvacuity. I critically examine various examples of the purported scientific use of non-vacuous counterpossibles and argue that they are not convincing. They neither establish that scientific practice comes with a commitment to the non-vacuity of counterpossibles, nor that incurring such a commitment would be useful in scientific practice. I illustrate a variety of counterstrategies on behalf of orthodoxy.