John Meyer

This essay briefly describes a few of the problems associated with using personhood language to defend the right to life of the pre‐implantation embryo. Arguing that an immaterial soul explains the personal identity of an embryo is problematic for many people because there is no apparent spiritual activity in the unborn. While some scholars argue that the embryo has the potential to act as an adult person and thus should be protected from harm, others contend that potentiality alone is insufficient reason to ascribe special moral worth to the embryo in utero. For Thomas Aquinas, the soul is not only the life‐principle that organizes the human body, but it is also that by which the human being thinks and wills. By making suitable corrections to Aristotle's hylomorphic depiction of the soul–body relation, I suggest that a rational soul must be present from the moment of conception and that it is at the service of the person. What is of critical importance here is to accept that a human being is present from the moment of conception, something the vast majority of embryologists maintain, notwithstanding the inveiglement of those who state that the pre‐implantation blastocyst is simply a disorganized clump of cells

In this paper a formal framework is proposed in which variousinformative actions are combined, corresponding to the different ways in whichrational agents can acquire information. In order to solve the variousconflicts that could possibly occur when acquiring information fromdifferent sources, we propose a classification of the informationthat an agent possesses according to credibility. Based on this classification, we formalize what itmeans for agents to have seen or heard something, or to believesomething by default. We present a formalization of observations,communication actions, and the attempted jumps to conclusions thatconstitutes default reasoning. To implement these informative actionswe use a general belief revision action which satisfies theAGM postulates; dependent on the credibility of the incominginformation this revision action acts on one or more parts ofthe classified belief sets of the agents. The abilities of agents formalizeboth the limited capacities of agents to acquire information, and the preference of one kind of information acquisition to another. A very important feature of our approach is that it shows how to integratevarious aspects of agency, in particular the (informational) attitudesof dealing with information from observation, communication and defaultreasoning into one coherent framework, both model-theoretically andsyntactically.

Knowledge has been a subject of philosophical study since ancient times. This is not surprising since knowledge is crucial for humans to control their actions and the appetite for acquiring it seems innate to the human race. Philosophy, therefore, has always occupied itself with the question as to the nature of knowledge. This area of philosophy is generally referred to as epistemology from the Greek word for knowledge: episteme. Plato defined knowledge as “justified true belief,” and this definition has influenced philosophers ever since; cf. Gettier and Pollock. Although sensible, this definition does not yet explain the nature of knowledge, since all of the three notions of ‘justification’, ‘truth’, and ‘belief’ are not yet clear and still subject to discussion. It would go beyond the scope of our purposes here to go into this at this moment, but it is touched on later in this chapter.