The last decade has witnessed a profusion of commentary on “mind-reading” devices. Instead of offering traditional legal arguments against such devices, most scholars have simply assumed their use to be unconstitutional. The consensus is clear: by essentially “speaking for” defendants, mind-reading devices offend the basic spirit of the Self-Incrimination Clause. In this Article, I defend the constitutionality of mind-reading on both doctrinal and normative grounds. First, I reconstruct the Court’s self-incrimination jurisprudence to demonstrate that evidence is only “testimonial” — and thus, privileged — if it involves a “communicative act” from the suspect. Whether or not particular types of mind-reading devices would elicit “communicative acts” is a narrow, technology-specific question. And at least some mind- reading devices almost certainly would not – making their use permissible under the Fifth Amendment. Second, I defend this doctrinal result against normative attack. Many different accounts of the privilege’s theoretical underpinnings exist. I evaluate these accounts in turn, arguing that some are inapposite to mind reading, while others fail in a deeper sense.