The Simple Solution to Personal Identity

The question of what defines a person, as a unique entity separate from all other people, has been a topic in philosophy for centuries. In recent years it has cropped up with more urgency, largely due to the growing possibility of technology to “upload” a person’s mind into a digital substrate. This mind uploading has been the topic of both serious research (e.g. Whole Brain Emulation: A Roadmap) and popular media (e.g. Upload). As a result, discussions on the internet have frequently spun around in the same circles, with some observers claiming that an upload is obviously “just a copy” (and not the same person as the original), while others feeling it no less obvious that a perfect copy is the same person as the original. The two groups come to exactly opposite conclusions about whether mind uploading would be a useful technology for survival. (One could make the exact same arguments about the science-fictional transporter, though writers frequently hand-wave away the issue and dodge the hard questions in this case, making it less commonly the inspiration for serious discussion.)

On the Uses and Limitations of Common Sense and Intuition

Often arguments about personal identity begin or end with an appeal to common sense or intuition, i.e., a conclusion that is obviously true. To some, it may be obvious common sense that two copies of a person are two different people; to others, it is just as obvious that they are the same person. Yet that doesn’t mean common sense is never useful; on the contrary, any good theory of personal identity should match our common-sense conclusions, in certain scenarios. Exploring the origins of common sense, when it is useful, and why it sometimes fails to serve us is the topic of this essay.

How to Recognize a Sound Philosophy

In mathematics, a new theorem can be subjected to a rigorous proof, which any mathematician in the field can verify. In science, a hypothesis can be shown to be in agreement with data to some desired level of probability. In philosophy, things are not quite so rigorous. But that does not mean one philosophical argument is as good as any other! A philosophy can be fully solid and sound, or it can be complete nonsense – or, like most things in life, it can be somewhere in between. Fortunately, there are reliable ways to judge, through careful analysis, the soundness of a philosophical position.