In what situation can multiple experts validate a learned treatise?

Multiple experts can validate a learned treatise if they are from the same field and agree on its contents. This validation occurs because learned treatises are recognized as authoritative sources within a particular field of expertise. When multiple experts, who have relevant qualifications and experience, concur with the information or opinions presented in a treatise, it reinforces the credibility of that treatise as a reliable source of knowledge.

The agreement among experts serves a crucial role in establishing the treatise as accepted within the scientific or professional community. Their collective acknowledgment can help demonstrate that the treatise's assertions are widely recognized and supported by knowledgeable individuals within the relevant discipline, making it more likely for its contents to be admitted as evidence in court.

In contrast, being published authors of the treatise does not inherently validate its contents, as individual authorship does not necessarily reflect consensus or acceptance in the broader field. Membership in a professional organization, while indicating a certain level of expertise, does not ensure that members agree on the treatise's contents. Testifying on unrelated matters lacks relevance to the validation of a treatise, as it does not provide insight into the treatise's acceptance or authority within the pertinent field.