I. Introduction: the problem of personal diachronicity
The need to determine the same person, which requires an elaborately constructed theory, arises from reflection and doubt upon an intuitive sense of unity present in each conscious individual.1 This essay will prove that autonomy and adaptability are key types of sameness that makes the author in the present and the author ten years ago the same entity positioned in different points of time.
The question of identity is often approached from a logical and objective standpoint in philosophy. However, philosophers have long wrestled with the concept of cross-temporal personal identity, dubbed personal diachronicity, which captures an individual's sense of continuity and sameness despite the physical changes that occur over time. Unlike the logical and objective perspective, personal diachronicity arises from the subjective and intuitive aspects of human perception, making it a complex and nuanced aspect of identity to explore.2,3,4
If we recognize subjectivity and intuition as primary sources of the self, there should be no questions regarding the concept, as the feeling of sameness is a-theoretic, i.e. does not need to be proven to be true.5 In other words, the statement that I am the same person as ten years before is correct because I feel so indeed. On the contrary, if we view the problem objectively, conflicts immediately appear as to how a person maintains the feeling of the self in the face of physical changes. This conflict will be the center of philosophical interest of this essay.
If we accept the grounds for the philosophical problem of personal diachronicity, the question at hand will be how to provide an alternative basis to understand the phenomenon of personal diachronicity without relying on the self-justification of subjective experiences, able to explain the phenomenon even when the subject of apprehension isn’t the observers themselves.
This essay will propose one solution to the problem of personal diachronicity in two parts. In the first part, I will define what is demanded to fulfill the analytical requirements of an identity theory, reaching a two-parted conclusion: explanatory power and rigorousness. In the second part, I’ll further examine two candidates: the memory approach and the intelligence approach, and reach the conclusion mentioned in the first paragraph.
II. Seeking an identity: Where are we looking at and what are we looking for?
The degree of change in a person cannot be underestimated. The species of Homo Sapiens present a stark contrast to other species. For example, swarms of bees exhibit remarkably consistent behaviors that have remained largely unchanged for thousands of years, evolving gradually over extended periods. This is because their actions are determined solely by biological traits. In contrast, a single human can witness the drastic changes of social norms over the mere span of a decade, say, 1930-1940. 6
Adding to the influence of changing social norms, an individual grows substantially both physically and mentally over 10 years, especially considering that the subject in question (myself, the author) 10 years ago didn’t undergo the turbulent changes of adolescence. Humans also exchange cells, gain and lose weight, acquire skills and preferences, switch goals, etc.
What to look for
Presented with such degrees of change, what is required from an identity theory?
Firstly, the theory should provide detailed and explicit explanation of the mechanism of personal diachronicity.
Secondly, the theory should be consistent with the object it seeks to explain. Whenever personal diachronicity persists, the theory should be able to provide justification; the situation in which personal diachronicity exists while the theory fails to apply will thus falsify the theory. The identity on which the theory focuses should possess a degree of transitivity matching that of personal diachronicity.
Where to look at
As the material composition of an individual is subject to substitution (some even contend that one’s entire atomic composition is replaced every ten years),7 this essay will focus on the aspects of consciousness and perception.
In fact, compared to the drastic changes of other organs, the vehicle of perception-the brain, remains largely constant and the number of brain cells remain fixed. Moreover, in the history of medical science, no organ transplants would cause identity crises i.e. the annihilation of the self without meddling with the brain.8 The unique link to perception makes it disproportionately relevant.
Subsequently, in a hypothetical thought experiment placed in the future, I extract my memories and knowledge and deploy the information to an advanced automaton. The automaton, conscious and capable of action, is able to serve as an avatar continuing my identity.9,10 Hence, I conclude that it is a sort of abstract information or the mobilizing force of which in the realm of perception on which personal diachronicity depend.
III. The first approach: Memories
The continuity provided by our "autobiographical memories"11 plays a central role in shaping our understanding of ourselves and enables us to navigate the complexities of personal development.
Consider also, a person with Alzheimer’s disease without access to past memory. The person would consequently lose track of life, connections with others, knowledge obtained in the past and also, the feeling of a concrete self. Hence, through memories, one presumably attains the feeling of sameness. John Locke, for example, states that "personal identity, the sameness of a rational being—consists in consciousness alone", and the extent to which the consciousness of an individual extends into the past depends on whether this person possesses records of past actions and thoughts.12 In other words, two individuals at different timepoints are the same if person A at timepoint tA remembers having done things performed by person B at tB.13
However, the memory approach is not flawless. The most commonly-visited objection towards the approach focuses on transitivity, as gaps exist between the segments of episodic memories of each subjective entity.14 Though the author still retains the broad outline of major events which he experienced as a 6-year-old, he is incapable to recall a persistent stream of precise memories of actions and thoughts during that period. If the transitivity of memories establishes the continuity of the self, then the absence of which should logically deny the continuity of the author. As many have pointed out, this falsifies the theory as the level of transitivity of memories does not match that of personal diachronicity. Humans are all prone to forgetfulness while retaining episodic memory precisely is also a considerable challenge. One could therefore argue that the transitivity of memory is too strict a principle, failing to justify all instances of personal diachronicity.
One plausible response, proposed by Reid, involves the transitivity of sameness: if A at tA possesses episodic memory of B at tB, and B at tB that of C at tC, then A should be identical with B, which should be identical with C. Thus by mathematical logic of equations, A = B = C.15
The robustness of this response is questionable for it doesn’t provide explanation when faced with incompabilities. In the case mentioned above, if A does not retain episodic memory of C, the transitivity of memory would suggest that A should not be equivalent to C in the first place. In this case, A is both C and not C, leaving the question in its best, a paradoxical standoff which urges more alternative approaches.
IV. The second approach: Intelligence as a machine
Disciplines like neuroscience and psychology focus on interpreting phenomenon of the brain, making them largely restrained by the level of technology in data collection e.g. fMRI, neural sensors etc. Moreover, the correlated phenomena might be the common epiphenomena under the same function, presenting a degree of circularity.
The second approach doesn’t depend on analyzing phenomena and specific physical aspects of the container of perception—the brain. Instead, it focuses on recreating the studied material self and ruling out aspects that are irrelevant and unnecessary. The approach views the mind not as a bundle of phenomena, but as a machine of a particular purpose. Machines, unlike purely passive natural objects, possess a degree of independence and autonomy, as it employs its own laws and mechanisms to interact with the physical laws of nature, achieving the designed purpose. Therefore, examining the mind under this framework sheds light on the mechanism of personal diachronicity.
Definition of intelligence
Before delving into a thorough examination of the intelligence as a machine approach (referred to as the intelligence approach below), it is essential to provide a concise definition of the term "intelligence". In the realm of science, intelligence is a multifaceted concept that emphasizes a fundamental function of the brain.16 It encompasses several key aspects, including:
1. The ability to process and interpret signals from the environment, transforming them into abstract information that can be understood and analyzed.
2. The capacity to react, affect the material world and achieve desired outcomes.
3. The capability to summarize experiences and develop knowledge, discerning patterns that can be applied in similar future situations.
According to information scientists, intelligence, whether natural or artificial, can be manifested through the application of specific laws.17 Each system of intelligence operates based on its own set of laws, and the generation of phenomena can be seen as the interplay between these laws and the physical laws of the external world. Over the past 50 years, scientists in the field of artificial intelligence have effectively utilized this concept to define, evaluate, and construct complex intelligent systems with distinct qualities.18 It is my contention that the laws of intelligence serve as the foundation for personal diachronicity.
Autonomy, as the first law of intelligence, provides two insights into the problem:
Survival: The primary goal of an intelligent system is to ensure its own preservation and development over time. Autonomy places the existence of the self at the highest level of priority, guaranteeing that the self continues to function and thrive. This aspect of autonomy supports the notion of personal diachronicity, as it emphasizes the importance of the continuity of the self’s existence throughout different periods of time. The reasoning follows that the survival of the self ten years ago is essential to the existence of the self today, reinforcing the sense of personal identity over time.
Self-regulation: In order to achieve the aforementioned goal of survival, an intelligent system must maintain control and governance over the various components of its bodily structures. Autonomy ensures that the self exhibits hierarchic control over its different functions and processes, and over other parts of the body, mobilizing them to function as desired. By exercising self-regulation, the self attains a sense of continuity and agency, further reinforcing personal diachronicity.
Through the principle of autonomy, the intelligence approach provides support for the concept of personal diachronicity. It highlights the significance of survival and self-regulation in maintaining the continuity and coherence of the self over time, offering a foundation for understanding and exploring personal identity within this framework.
Adaptability, as the second law of intelligence, plays a significant role in supporting the concept of personal diachronicity within the framework of Intelligence as a machine. In the field of cybernetics, which examines connections between behaviors, information, and intelligent machines, adaptability is regarded as a fundamental aspect of every intelligent system.
According to cybernetics, intelligent systems rely heavily on the feedback loop—a process in which the system receives feedback information from the environment, undergoes self-changes, and adapts its behavior accordingly. This principle of adaptability applies to personal diachronicity as well. The present self is intricately connected to the past through a series of dynamic and continuous optimization and evolution, driven by the accumulation of information and experiences over the years.
V. Conclusion
The intelligence as a machine approach provides a framework that fulfills the requirements of this essay, particularly in understanding personal diachronicity. By emphasizing the laws of intelligence, this approach offers a comprehensive perspective on personal identity over time. In conclusion, it is sufficient to claim that I am the same person as ten years before because the aforementioned aspects of autonomy and adaptability connects us together as the same intelligent entity.
Notes
1. The essence of the topic question might be best captured by the illuminating remark made by Steve Grand, in his book Creation: Life and How to Make It, and is cited below:
"Think of an experience from your childhood. Something you remember clearly, something you can see, feel, maybe even smell, as if you were really there. After all, you really were there at the time, weren’t you? How else would you remember it? But here is the bombshell: you weren’t there. Not a single atom that is in your body today was there when that event took place … Matter flows from place to place and momentarily comes together to be you. Whatever you are, therefore, you are not the stuff of which you are made. If that doesn’t make the hair stand up on the back of your neck, read it again until it does, because it is important."
Bibliography
2. Klein, S. B. (2014). Sameness and the Self: Philosophical and psychological considerations. Frontiers in Psychology, 5, Article 29. https://doi.org/10.3389/fpsyg.2014.00029
3. Dainton, B. (2008). The Phenomenal Self. NY: Oxford University Press.
4. Gallagher, S., & Zahavi, D. (2008). The Phenomenological Mind. NY: Routledge.
5. Kant, I. (1998). Critique of Pure Reason, The Cambridge Edition of the Works of Immanuel Kant, Edited by Guyer P. & Wood A.W., NY: Cambridge University Press
6. Harari, Y. N. (2015). Sapiens: A Brief History of Humankind, NY: HarperCollins Publishers
7. Grand, S. (2003). Creation: Life and How to Make It, MA: Harvard University Press
8. Noonan, H. W. (2003). Personal Identity, 2nd Edition, London: Routledge
9. Wiggins, D. (1971). Identity and Spatio-Temporal Continuity. Oxford: Blackwell.
10. Focquaert, F. (2003). Personal identity and its boundaries: philosophical thought experiments. Philosophica, 72: 131–152.
11. Fivush, R. & Haden, C. A. (2003). Autobiographical Memory and the Construction of a Narrative Self: Developmental and Cultural Perspectives. NY: Psychology Press.
12. Locke, J. (1998). An Essay Concerning Human Understanding. NY: Oxford University Press
13. Shoemaker, S. (1963). Self-knowledge and Self-identity. London: Oxford University Press.
14. Tulving, E. (1983). Elements of Episodic Memory. London: Oxford University Press.
15. Thomas, R. (2011). Essays on the Intellectual Powers of Man, Cambridge: Cambridge University Press
16. Sternberg, R. J. (2012). Intelligence, Dialogues in Clinical Neuroscience, 14 (1): 19-27
17. Molina, M. (2022). What is an intelligent system? arXiv:2009.09083v3, https://doi.org/ 10.48550/arXiv.2009.09083
18. Zhu, S.Q., Yu, T., Xu T., et al. (2023). Intelligent computing: The latest advances, challenges, and future, Intelligent Computing, 3: Article ID: 006, doi: 10.34133/icomputing.0006