- When did I begin to exist?
- This is a question that has been asked many times in the past and is now asked again with renewed urgency. The reply I will give is certainly not new, but it will be reached invoking a piece of relatively recent evidence that I hope will also allow me to provide a fresh insight into the phenomenon of twinning. My main goal in this paper is critically to examine the thesis vigorously argued by Barry Smith and Berit Brogaard (S&B1) that sixteen days after fertilization marks the inception of a human individual.
- I shall first introduce some of the terms that I will be using.
- An adequate reply to the question about my beginning is a function of the proper sortal under which I fall. If “married person” is a proper sortal for me then I began to exist in 1963 (with the welcome consequence that my beloved wife began to exist at the same time I did). But “married person” surely stands for a phase sortal. It is a sortal such that someone who ceases to fall under it does not necessarily cease to exist. People, of course, exist before and after being married persons.
- On the other hand, a proper sortal (or “substance sortal”, as Michael Lockwood calls it) is coextensive in time with the object that falls under it. Before beginning to fall under a proper sortal the object did not exist, and after it ceases to fall under this sortal it ceases to exist. To begin to fall under a proper sortal is called in Aristotelian metaphysics “generation” or “coming-to-be”, one of the two forms of substantial change. The other one is “corruption” or “passing-away.” For the change from one phase sortal to another, that is, for a change in non-substantial attributes, the term employed is “alteration”. I will use it in the broad sense in which it is not limited to the category of quality. Growth, for example, a change in quantity, will count as an alteration. Alteration does not entail loss of identity whereas substantial change does. A change that drastically modifies the nature of a thing will count as a substantial change.
- Finally, I would like to add that I will call “thing” or “substance” something that can exist in its own right and “attribute’ or “property” something that can only exist insofar as it inheres in a substance. A person who walks is a substance, but walking is an attribute of a substance. Walking cannot exist by itself.
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- Blue: Text by me; © Theo Todman, 2021
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