Using the example of Person 1 at time T1 and Person 2 at time T2. The person is considered to be the same, if they share the same soul, but from the argument Gretchen used before we cannot see the soul, so we can never assume that the soul of the two people is the same. Even if the two people share similar characteristics of the soul, the soul could be ever-changing and we can never assume that the soul is the same for Person 2 at time T1 and Person 2 at time T2. Gretchen uses the example of the Blue River to describe this concept. Although the blue river is always visible and people can assume that it is the Blue River based on the characteristics it has, we cannot assume with certainty that it is the blue river. The composition of the river might be similar when looking at it, but the particles of water are never truly the same. The particles are always changing. This is similar to the concept that sameness of the body cannot be equivalent to sameness of the person. Similar to the Blue River, the body might appear to be similar at various time points, but the true composition of the soul cannot be confirmed confidently. This explains why we cannot know that a person at time T1 is the same person as the person at time
Using the example of Person 1 at time T1 and Person 2 at time T2. The person is considered to be the same, if they share the same soul, but from the argument Gretchen used before we cannot see the soul, so we can never assume that the soul of the two people is the same. Even if the two people share similar characteristics of the soul, the soul could be ever-changing and we can never assume that the soul is the same for Person 2 at time T1 and Person 2 at time T2. Gretchen uses the example of the Blue River to describe this concept. Although the blue river is always visible and people can assume that it is the Blue River based on the characteristics it has, we cannot assume with certainty that it is the blue river. The composition of the river might be similar when looking at it, but the particles of water are never truly the same. The particles are always changing. This is similar to the concept that sameness of the body cannot be equivalent to sameness of the person. Similar to the Blue River, the body might appear to be similar at various time points, but the true composition of the soul cannot be confirmed confidently. This explains why we cannot know that a person at time T1 is the same person as the person at time