¹³A threat has been defined as “anticipation of potential harm” (Palmwood and McBride (2019) based on Folkman and Lazarus). In our formalism, this could tentatively be translated as “prediction of likely (large) reduction in state-value” (or, in a short-sighted calculation, prediction of likely negative reward); the computational definition of threat is an important topic for future research. In the narrow context of self-preservation, we could also talk about the prediction of likely destruction (or death). Our definition is different from what is often given in the literature, where a threat is defined in a social, interpersonal, or legal context, and it is an act made by one agent towards another. In this book (as well as in Cassell’s definition of suffering, in my interpretation), threat is not interpersonal in most cases. Yet, any definition of an interpersonal threat could be applied here by assuming that “nature” is the other agent making the threat.