Self-identity or the knowledge of one’s existence is a seemingly obvious question with very few (logically) satisfying answers. The 18th-century Scottish philosopher David Hume argued that there is no such thing as a self or personal identity. What we call our identity, for Hume, is the mere collection of perceptions that are produced on account of our experiences. In his magnum opus, a treatise on human nature, he famously said that “the identity that we ascribe to things is only a fictitious one, established by the mind, not a peculiar nature belonging to what we’re talking about”.
In this rather short piece, I argue that while I do not have the certain knowledge to affirm my existence, I have probable reason to believe as such. Rene Descartes argued that because we can think, or in other words, perceive ourselves, therefore we must exist – “cogito ergo sum’. He further maintains in his book Meditations on First Philosophy, that even if our perception of self-identity was induced by a mighty demon, we would need to have a “mind”, and therefore – we would need to exist; “exist”.
Evidently, Descartes and Hume have contrasting opinions on the existence of the self but neither argument is invalid (typical of philosophical theories). Hume’s arguments do not deny the existence of self-identity but rather deny the existence of a ‘unified self’ (Roth, 2000). Meaning, he argues that what we call self, is an ever-changing entity and is not fixed for anyone to point out, ‘this is me’. Whereas Descrates’ argument is concerned with self-identity in general. Meaning that the self may be or in fact. is a changing entity but it exists – regardless of its dynamic nature.
What to ask?
To say that I exist is logically too demanding a proposition and our inquiries on the subject matter are stuck on paradoxes. However, we can claim that we exist, not as unified selves but as thinking beings whose existence by nature has the potential to change over time. One might ask, what logical reasons do we have to support the claim that we exist?
The reason to believe in the existence of sense, in general, is what Descartes proposes in the Meditations on First Philosophy, “I think therefore I am.” To reiterate, because we have the ability to think, we exist. But how can we know that the thinking being we are addressing is us? We know because we can address it. Even if it is a hallucination or any other form of false belief, we are in fact addressing an entity. Meaning, the self may be different than what we think it is, but it is, even if we deny its existence, it is we, or “I” that is denying the existence of “my” self-identity.
How do we know something to be true? The primary faculty that we have to answer this question is our rational mind. And then we have our senses. Our sense experiences, after being rationalized by our minds, shape our perceptions. We can doubt our perceptions for valid reasons and in this case, we can and should doubt our self-identity (Williams, 2014).
Moreover, the question, of how I know if I exist as a unified self, has a predicament. For instance, the question presupposes that a person already has the knowledge of what it means to exist. And if one already had the knowledge, they must exist. The question has this presupposition, meaning that it has set conditions for something to be true in advance. The question makes this assumption otherwise, it is not plausible to imagine that we will know exactly how we exist. Because, as mentioned, our minds rationalize our sense experience and then believe a certain thing to be true based on a cause-and-effect relationship. However, in this case, we cannot possibly say with certainty that X is a unified self.
However, Descartes in ‘Meditations on the First Philosophy’ concludes that we exist because God has allowed us to. He needed this explanation and came up with it because, without a cause-and-effect relationship, it was not possible for him to believe it to be true.
Finally, we cannot deduce concrete evidence for anything to be true, including our self-identity and we cannot have certain knowledge because the cause-and-effect relationship, which is the most important and reliable way to be certain about our knowledge, cannot always be satisfied. But we can be doubtful. And we can exist, even in doubt.
Descartes, R., & Veitch, J. (1641). Meditations on First Philosophy. Independently published.
Hume, D. (1739). A Treatise on Human Nature. Franklin Classics.
Roth, A. S. (2000). What was Hume’s Problem with Personal Identity? Philosophy and Phenomenological Research, 61(1), 91. https://doi.org/10.2307/2653404
Williams, B. (2014). Descartes. Descartes: Pure Inquiry. https://doi.org/10.4324/9781315747439