This paper analyzes the transformation from the human zygote to the implanted embryo under the prism of substantial change. After a brief introduction, it vindicates the Aristotelian ideas of substance and accident, and those of substantial and accidental change. It then claims that the transformation from the multicelled zygote to the implanted embryo amounts to a substantial change. Pushing further, it contends that this substantial change cannot be explained following patterns of genetic reductionism, emergence, and self-organization, and proposes Gustavo Bueno’s (...) idea of anamorphosis as a means to encapsulate criticism against such positions. (shrink)

In some quarters, it is held that Anscombe proved that a zygote is not a human being on the basis of an argument involving the possibility of identical twins, but there is surprisingly little agreement on what her argument is supposed to be. I criticize several extant interpretations, both as interpretations of Anscombe and as self-standing arguments, and offer a different understanding of her conclusion on which the non-specificity of creation processes and their goals is at issue.

It has been argued that the possibility of monozygotic twinning disproves the conservative position on foetal personhood that defines the foetus as a person from conception. This article will canvass arguments for and against this proposition, in order to arrive at a conclusion as to the relative strength of this finding.

A basic component of moral objections to embryonic stem cell research is the claim that human embryos have the same moral status as typical adult human beings. There is no reason to accept this claim, however, unless adult humans once existed as embryos—that is, unless the developmental history of adult humans contains embryos to which the adults are numerically identical. The purpose of this paper is to argue that there are no such identities, and hence that no adult human being (...) ever existed as an embryo. (shrink)

How many individuals are present where we see a pregnant individual? Within a substance ontological framework, there are exactly two possible answers to this question. The standard answer—two individuals—is typically championed by scholars endorsing the predominant Containment View of pregnancy, according to which the foetus resides in the gestating organism like in a container. The alternative answer—one individual—has recently found support in the Parthood View, according to which the foetus is a part of the gestating organism. Here I propose a (...) third answer: a pregnant individual is neither two individuals nor one individual but something in between one and two. This is because organisms are better understood as processes than as substances. With a special focus on the Parthood View, I explain why a Process View of pregnancy, according to which a pregnant individual is a bifurcating hypercomplex process, surpasses the substance ontological approaches. (shrink)

Do pregnant mothers have fetuses as parts? According to the “parthood view” they do, while according to the “containment view” they don’t. This paper raises a novel puzzle about pregnancy: if mothers have their fetuses as parts, then wherever there is a pregnant mother, there is also a smaller thinking being that has every part of the mother except for those that overlap with the fetus. This problem resembles a familiar overpopulation puzzle from the personal identity literature, known as the (...) “Thinking Parts Problem”, but it’s not merely a special case of that problem. Rather, the fact that late-term fetuses have a mental life of their own makes the Problem of Pregnant Thinkers, as I will call it, a sui generis and especially recalcitrant problem. (shrink)

Is the mammalian embryo/fetus a part of the organism that gestates it? According to the containment view, the fetus is not a part of, but merely contained within or surrounded by, the gestating organism. According to the parthood view, the fetus is a part of the gestating organism. This paper proceeds in two stages. First, I argue that the containment view is the received view; that it is generally assumed without good reason; and that it needs substantial support if it (...) is to be taken seriously. Second, I argue that the parthood view derives considerable support from a range of biological and physiological considerations. I tentatively conclude in favour of the parthood view, and end by identifying some of the interesting questions it raises. (shrink)