what person stands for; which I think, is a thinking intelligent being that has reason and reflection and can consider itself as itself, the same thinking thing in different times and places; which it does only by that consciousness which is inseparable from thinking and, as it seems to me, essential to it …. For since consciousness always accompanies thinking, and it is that that makes everyone to be what he calls self, and thereby distinguishes himself from all other thinking things: in this alone consists personal identity, i.e. the sameness of a rational being. (chap.27, para. 9)
Not all of this is as clear as it could be, and philosophers have offered slightly different interpretations of Locke’s concept of personal identity, and thus of his concept of a person. What is crucial here, however, are not the details, but simply that, on Locke’s account, a person is an entity that (1) has conscious mental states at some times, (2) has the capacity for thought at some times, and (3) has thoughts at some times that are mentally linked to conscious states at other times.
Locke’s concept of a person is clearly very different from his concept of a human animal. It could turn out, of course, that all human animals, at any time, are in fact persons, in Locke’s sense. We shall see shortly, however, that there are very strong scientific arguments against that possibility.
1.2 The concept of a neo‐Lockean person
I shall sometimes use the expression “neo‐Lockean person,” and this for three reasons. First of all, as just mentioned, disagreements exist concerning the correct interpretations of the passages where Locke introduces his idea of a person, and no stand need be taken on that issue. Secondly one might want to include in one's concept of a person elements that Locke does not mention, such as desires concerning one’s mental states at other times. Thirdly, the term “person” is sometimes used, especially by those who believe that abortion is seriously wrong, in two other, very different ways: sometimes as a purely evaluative term, meaning simply “entity with a right to life,” and sometimes as a purely biological expression, meaning “member of the biologically defined species homo sapiens.” Such uses of the term “person” contain no reference at all to consciousness, or to the capacity for thought, or to any mental states whatsoever. The expression “neo‐Lockean person” functions, then, to rule out such interpretations.
Constant use of that expression, however, would become a bit tiresome, so I shall often simply use the term “person,” with the understanding that it is always an abbreviation of “neo‐Lockean person.”
What, then, do I mean by “person”/ “neo‐Lockean person”? The answer is that a neo‐Lockean person is an entity that has, at least at one time, a memory involving a conscious thought about an earlier state of consciousness. Something that has never enjoyed a single state of consciousness is thus not a neo‐Lockean person. Similarly, something that has never had a conscious thought cannot be a neo‐Lockean person. Finally, something that has never had a memory thought about an earlier state of consciousness cannot be a neo‐Lockean person.
A neo‐Lockean person exists, then, when the consciousness condition, the conscious thought condition, and the memory thought conditions are all satisfied.
1.3 Distortions of the concept of a neo‐Lockean person
Arguments are rarely offered against the view that only neo‐Lockean persons have a right to life, and when offered, they inevitably misrepresent the concept of a neo‐Lockean person. A typical example is Christopher Kaczor who, in his book The Ethics of Abortion, considers the following possible necessary conditions for existing as a neo‐Lockean person at a time: (1) being self‐aware at that time; (2) having an immediately exercisable capacity for self‐awareness; (3) having functional hardware that is a basis of the capacity for self‐awareness; (4) having an active potentiality for reacquiring a capacity for self‐awareness; (5) having a passive potentiality for reacquiring the capacity for self‐awareness (2014, 31–5).
All of this is a complete failure – or an unwillingness – to recognize what lies at the heart of the concept of a neo‐Lockean person, namely, the existence of a memory that, if accessed, will involve a thought about an earlier state of consciousness to which it was causally linked. All of us have some memories, however, that we are able to access at some times, though not at others, and the inability to access a memory at a given time does not mean that the memory no longer exists. So none of the conditions that Kaczor mentions are necessary for the continued existence of a neo‐Lockean person: as long as the memory exists, the neo‐Lockean person exists, and the memory exists as long as the neural basis for it exists.
1.4 Neo‐Lockean persons and the right to life
Imagine there are times when you have perceptual experiences and bodily sensations unaccompanied by any thoughts. Concerned, you contact your doctor, who tells you of a new virus that temporarily prevents you having any thoughts. Asking about your prognosis, you learn that the temporal gaps between such occurrences will gradually become less and less, until, finally, your ability to have thoughts no longer exists. You ask whether there is any treatment, and are told that there is a drug that, if successful, will completely cure you, but otherwise will kill you.
Consider, now, what it would be like to have sensory experiences and bodily sensations, but to have no thoughts at all at any time – no thoughts about your present experiences, no thoughts about what you did in the past, no thoughts when someone speaks to you, no thoughts about anything. What value would you assign to such a life?
Suppose p is the probability that the drug will cure you, and thus (1 – p) the probability that it will kill you. How high does p have to be for you to decide to take the drug at some point before you permanently lose the capacity for thought? The answer to that question will fix the value that a life lacking forever the capacity for thought has for you.
Many people I have talked to about this have said that they would ultimately opt for the drug regardless of how close to zero the value of p was. That, however, would imply that the extent to which one values the continued existence of a life with experiences and sensations, but with no capacity for thought, is essentially zero.
The idea is then that it seems plausible to think that there should be a connection between the extent to which people would value such a life and the intrinsic wrongness of killing a person with such a life. If so, the conclusion would be that the wrongness of killing a conscious being permanently lacking the capacity for thought is essentially zero, in which case it would be plausible to conclude that conscious beings permanently lacking a capacity for thought, and thus who are not neo‐Lockean persons, lack a right to continued existence.
Notice that the conclusion here is that being a neo‐Lockean person is a necessary condition for having a right to continued existence, and not that it is also a sufficient condition, since one might hold, as many philosophers do, that one must also have desires, preferences, or interests in order to have a right to continued existence, and neither Locke’s account of a person, nor mine, refers to such mental states. Whether such states are necessary for moral status is a deep and difficult issue in normative ethics, and happily, not one we need not explore here.
2 Cloning to Produce Human Organisms that Will Never Become Persons
2.1 Cloning for medical purposes or scientific research
Embryonic stem cells have proven important for drug discovery and in testing for toxicity, and they also show promise for the treatment of presently incurable diseases, since they can be used to produce different types of cells that can serve to repair damaged tissue (Cerva and Stojkovic, 2007.). To avoid rejection, however, the stems cells should be derived not just from any embryo, but from a clone of the patient.
2.2