Locke-1698-Identity-and-diversity = consciousness Reid-on-personal-identity = underlying self Baier-on-the-relational-view-of-self = social context
Both Locke-on-personal-identity and Reid-on-personal-identity give the basis for personal with the individual. In both accounts, there is an internal metaphysical principle for personhood, with little mention of interpersonal contexts and social relations. Baier-on-personal-identity grounds it in relation to other people.
Philosophical conception of identity
- Qualitative identity = two things are qualitatively identical if they have all the same intrinsic characteristics (or qualities). E.g. two pens from the same package
- Numerical identity = identity in the sense of being “one and the same.” E.g. you as a child and you now are one and the same person (just at different stages of life)
Puzzle of the Ship of Theseus
Theseus captains a ship that goes on a very long voyage carrying a cargo of timber. As the voyage proceeds, the ship needs repairs, so Theseus uses the timber in his cargo to replace damaged planks of the ship. Well, the voyage takes so long that by the time the ship arrives at its destination, every single plank of the original ship has been replaced by a new plank from the cargo.
Question: Is the ship that arrives at the destination numerically the same as the ship that initially set out?
I think the Ship of Theseus can be understood as both the same and not the same ship, depending on which aspect of identity we focus on. From a material perspective, it is not the same ship. All of the physical components—the planks, nails, and timbers—have been replaced, so in terms of substance it no longer shares continuity with the vessel that originally set out. However, from a historical and narrative perspective, it remains the same ship. It is still the vessel that belongs to Theseus, the one that embarked on that specific voyage at that particular time. Its story and role as “Theseus’ ship” continue uninterrupted, even though the materials have changed. Rather than demanding one definitive solution, the problem reveals how identity can have multiple dimensions—physical, historical, and conceptual—that may not always align, resisting a strict yes/no answer.