Psychological Continuity Theory Vs. Physiological Continuity Theory

Why the psychological continuity theory is more preferable than the physiological continuity theory of personal identity.

What makes a person the same over time? What changes or events can a person undergo whilst still staying the same and conversely what will cause the person to cease existence? These are questions of personal identity and its criterion is distinguishing between which changes or events conclude in survival or death. That being said, before speculating which occurrences may alter a person’s existence we must establish what constitutes a person’s identity to persist over time.

For this purpose identity is customarily split into qualitative identity and numerical identity. A person does not remain qualitatively the same over

Psychological properties implies all immaterial brain functions that comprise consciousness such as memory, personality and desires rather than the tangible substance of the brain itself. Since consciousness isn’t continuous throughout time such as when one’s asleep or experiencing a coma, to survive events of non-consciousness one must inherit the psychological properties of the person before the event. This process can be seen every time a person wakes up in the morning and derives the same psychological properties from when they went to sleep. However since some psychological properties such as memory may fade from these events of non-consciousness or naturally over time, for a specific person to continue life there must be an overlapping chain of brain function that connects one instance of time to another. Take for instance a person at t3 who doesn’t remember the events that occurred at time t1. As long as the person remembers a time t2 at which he could recall the events of t1, the by account of psychological continuity theory the person at t3 is the same person from t1. This notion of overlapping consciousness can be extended into the past to any action or event at varying times since birth, thus creating a person’s continual numerical identity from birth to

From this criteria of physiological continuity theory arose two famous respective theories. The first says that matter composing a person’s identity denotes all parts of the body from head to toe. However this quickly arises counter arguments as humans clearly loose aspects of their body over time and (whether it be an individual event or slow loss of cells) continue life. Hence the idea of a certain percentage of matter composing the body must remain from t1 for the continuance of personal identity at t2. This idea raises much fault as cases where such large proportions of a human have been replaced due to tragic events, and still been viewed to be the same person, thus putting this uncertain distinct “percentage” at question. The other less violable version of the physiological continuity theory focuses purely on the brain being the key matter that composes a person’s identity. This too rises the objection that many people undergo brain surgery where a significant portion may be removed, however there’s clear evidence that there is only a certain amount of the brain that can be withdrawn without arising fatal consequences. Therefore the concept of some certain unknown percentage required to be maintained for survival is a more plausible when singling out the