In 2009, the Court of Appeals for the Federal Circuit changed the landscape for trademark parties involved in claims of fraud on the PTO. With the issuance of its decision in the case In re Bose, the Court neatly upped the ante for plaintiffs to show “knowledge” and “willful intent.” However, as the dust began to clear from the case, and follow-on litigation ensued, an open question remained. Exactly what level of “knowledge” is required to plead and prove these claims of fraud on the PTO? Is recklessness sufficient? Might there even be another possibility? A footnote in Bose suggested the Court did not “resolve this issue,” thereby leaving it for future courts to decide. This article provides a framework for courts to use in approaching that decision. It begins with an analogy from patent law. As explained, the Supreme Court appears to be increasingly aligning patent law with general jurisprudence. In 2011, in Global-Tech v. SEB, the Supreme Court furthered that pattern by applying “willful blindness,” a doctrine from criminal law, to one of “actively inducing infringement,” in patent law. As explored by this article, patent and trademark (and copyright) law share common historical and legal origins. Accordingly, it seems appropriate to cross-apply doctrines between them, including, possibly, the recently applied doctrine of “willful blindness” adopted by the Supreme Court. If the Supreme Court intends to align patent law with other areas such as criminal law, as shown in the Global-Tech case, this article considers how much moreso it would have us extend that logic in deciding matters in the historically related areas of patent and trademark law (as well as copyright). Indeed, both the Supreme Court and Congress have indicated that they see trademark law as being related to patent law. Federal courts have followed this reasoning in cross-applying doctrines between (the three areas of) intellectual property law. Accordingly, this article considers the meaning and viability of “willful blindness” for claims of fraud on the PTO, while also considering “recklessness” and higher levels of “knowledge” as a standard for scienter, providing courts with the background and the options