Is a Sense Perception Always Unique?

[critch]

Is a sense perception always unique? When we see anything, we see it in time. Thus, the immediate image that is formed on our minds also changes as time passes. The ordinary example of this is that one can never see the same sunset twice. My students have struggled with this idea, so I'm trying to make sure I have it right. I use this to add a distinction between sense perception and mental image, since the latter is not unique, but repeatable. There may be a problem here with distinguishing between the mental acts and the content of those acts. Even so, couldn't I say that the act of sense perception is never repeatable in terms of content, but a mental projection is?

Charlie Ritch
Westminster School
Birmingham, AL