One of the main principles of the Hippocratic oath, which has guided medical practice for 2500 years, is Primum non nocere (first, do no harm). This means, among other things, that when the stakes are high (a patient's life) and one has no idea what one should do, it is better to do nothing at all than risk a treatment that might make things worse. We argue for a similar approach to a face-to-face first contact scenario. In such a situation, the stakes are literally the highest imaginable (the survival of humanity, perhaps even the entire terrestrial ecosystem), and we have almost nothing to go on – we will know next to nothing about our alien interlocutors and can not rely on our evolved instincts or simplistic analogies from Earth's history to guide us appropriately. The smart approach, therefore, is one of extreme passivity and caution. In particular, we argue that an inviolate “prime directive” needs to be imposed on any crew of a mission beyond near Earth such that they will do nothing, even in self-defense, that might potentially be considered threatening. While such a passive approach will forego many opportunities, first contact should be viewed primarily as setting the stage for second contact, with the goal of establishing the alien presence and communicating our harmlessness – no more. In the grand scheme of things, even the loss of the human crew is a small price to pay for the safety of the Earth and all its inhabitants.

希波克拉底誓言的主要原理之一（已指导医学实践2500年） 是非原发性（首先，不要伤害）。这意味着，除其他外，当风险高（患者的生命）并且不知道应该做什么时，最好什么也不做，而不是冒险做可能会使情况变得更糟的治疗。我们主张针对面对面的首次联系场景采用类似的方法。在这种情况下，赌注实际上是可以想象得到的最高赌注（人类的生存，甚至整个陆地生态系统的生存），而且我们几乎无所事事–我们几乎不了解外星人对话者，也不能依靠我们从地球历史演变而来的本能或简单化的类比中可以适当地指导我们。因此，明智的方法是极端被动和谨慎的一种。特别是，我们认为，必须对地球附近以外执行任务的任何机组施加违反的“主要指令”，以使他们即使在自卫时也不会做任何可能被认为具有威胁性的事情。虽然这种被动的方法会放弃很多机会，但第一次接触应主要被视为为第二次接触打下基础，其目的是建立外星人的存在并传达我们的无害化，而不再。在宏伟的计划中，即使人员丧生也是为地球及其所有居民的安全付出的很小的代价。旨在建立外星人存在并传达我们的无害化的目标，仅此而已。在宏伟的计划中，即使人员丧生也是为地球及其所有居民的安全付出的很小的代价。旨在建立外星人存在并传达我们的无害化的目标，仅此而已。在宏伟的计划中，即使人员丧生也是为地球及其所有居民的安全付出的很小的代价。