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Could a zygote be a human being?

¹University of Wollongong, Wollongong, New South Wales, Australia. jburgess@uow.edu.au

|December 17, 2008

Summary

This summary is machine-generated.

Human conceptionism, the view that human beings exist at conception, faces challenges from early fetal development. Early zygote development, including twinning and fusion, and the development of the placenta, contradict this view.

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Area of Science:

Developmental Biology
Philosophy of Biology
Bioethics

Background:

Conceptionism posits that human beings exist from the moment of conception.
Early human embryonic development presents unique cases, such as zygote splitting and embryo fusion.
These developmental phenomena raise questions about the identity and status of the early zygote.

Purpose of the Study:

To re-examine the philosophical position of conceptionism in light of early human fetal development.
To assess the tenability of conceptionism when confronted with cases of embryonic fission and fusion.
To explore the implications of placental development and inner cell mass formation for conceptionism.

Main Methods:

Philosophical analysis of conceptionism.
Examination of biological cases: zygote splitting (fission) and embryo fusion (chimera formation).
Evaluation of two potential conceptionist responses: the Replacement View and the Multiple Occupancy View.

Main Results:

Conceptionism struggles to account for zygote fission (twinning) and embryo fusion (chimeras).
Neither the Replacement View nor the Multiple Occupancy View adequately resolves these issues for conceptionism.
The zygote's development into both an embryo and a placenta, and the timing of inner cell mass formation, further challenge conceptionism.

Conclusions:

The paper argues that conceptionism is not tenable due to the complexities of early human fetal development.
Developmental events like twinning, fusion, and differentiation challenge the notion of a fully formed human being at conception.
The timing of the inner cell mass development complicates the conceptionist view, leading to problematic conclusions.