Contemporary consciousness research has given rise to numerous theories in both the philosophical and neuroscientific domains (such as higher-order theory and global neuronal workspace), raising the question as to how well each is supported. This article develops a relatively novel method for determining this, which is to use evidence, not just from a theory's own domain, but also from its complementary domain (e.g., neuroscientific evidence is used to judge a philosophical theory, and vice versa). This approach works when a neuroscientific and a philosophical theory are conceptually linked, allowing evidence confirming or disconfirming one theory to do the same for the other. After developing this method, the article uses it to draw conclusions concerning some of our leading neuroscientific and philosophical theories of consciousness, including first- and second-order representationalism and theories emphasizing the prefrontal cortex's role in consciousness.