What is identity? It's a long story.
Ascriptions of identity happen in the mind at the level of conceptualization, and not at the lower level of perception. While perception supports a faculty of categorization which is invariant to many sensory perturbations, such as lighting conditions and partial occlusions in the case of vision, this categorical invariance with respect to sensory perturbation is not the same as object identity.
Even the recognition of objects is not the same as recognizing them as having comparable identities. A mind can know about objects, as parts of a data stream which can be modeled separately, and yet still not know about their physical separation, persistence, or identity. Let me explain.
I was trying to imagine different ways an AI could analyze a video in order to tease out my implicit ideas of how the mental processes of conception differ from and build on perception. Here's the hypothetical: An AI could have an assumption of persistence for some features, like that there will keep being a bird with a bowler hat in each successive frame of the video, and not assume persistence in other features, like the AI could be unable to guess that the bird has a cane behind its body which was seen in a previous frame.
Is this AI seeing samples from the class of "bowler hat birds" and not relating them across times? Or is it successfully forming a very limited concept of identity whose only identity criterion is "be a bird with a hat"?
The answer could be either one, depending on the details of the AI, but pondering that question led me to a description of what it means for an agent to identify a thing as existing in two percepts rather than for it to merely make the same sensory categorization about the contents of the two percepts: Percepts of two instances of a category (two different bird pictures) have similarities which are genetic (arising in the past, after which the things could go their separate ways and never meet each other or their maker again) while two views of one object have similarities because of persistence or conservation (locally, spatially, through intervening times). "This bird" isn't the very narrow category of "birds with all features presently observed to be persisting". "This bird" differs from "a bird just like this" in that the mind assumes an intervening history transforming the features observed in or inferred from one percept into those features observed in or inferred from another percept.
If the AI has no conception of identity, it will just see a sequence of samples from the category of Bowler Hat Birds, and the AI will having nothing to say on whether they're the same or different birds. Despite having learned persistence of features and sensory categorization, it will not have learned Identity, and the question of whether the bird in the second frame has a tiny cane behind its back will be answered at some ignorant base rate (for birds or for canes, about which the AI could well reason separately). If the AI does have a notion of identity, then it could tell us it sees a sequence of different Bowler Hat Birds or one persisting Bowler Hat Bird, depending on its personal categories. But whether it sees them as the same or different, that judgement will be based on whether it suspects there was a causal history in which the objects depicted in the first video frame became the object in the second video frame. If such a transformation is plausible, and would not have entailed the destruction of the tiny cane, then hey presto, we have a plausible inference at the level of conceptualization enabled through through the ascription of identity.
In summary, objecthood at its lowest level might be interpreted as something like learning separation of background and foreground in a sensory stream. Learning that the feature values of an object or the sensory categories of an object are persistent in time is not enough to license other inferences across time which Identity allows, such as supposing that this bird has a tiny unseen cane behind its back. Maybe that's not impressive to you because the AI could have learned object persistence for the cane too, but Identity also lets us do counterfactual cross-temporal density estimation for unobserved features of the bird: like if she has cancer in one frame, she'll probably still have cancer three seconds later. And finally, Identity means supposing a local transformative history (as an explanation for the similarities which allow cross-temporal density estimation) rather than a genetic similarity of the category (in which case observed dissimilarities could be written off as within-category variance).
So that's a good start at what I think Identity is. It might be more complicated. Maybe it can only be the same Bowler Hat Bird in the second video frame if the hat stayed on the whole time between frames. If so, would that specifically be part of the criterion of identity for Bowler Hat Birds, or does continued identity require continuity of identity generally? I don't know. Hard question. Important question. Not for tonight.
Simple Songs For Sarah Sparks
Here are some songs I like, which, if I've sorted through them well enough, can be played on guitar without using any barre chords. Some of the chords do require four fingers, like A/C# and D7/F#, but for these, you can just leave out the bass notes that follows the slash. "Slip Sliding Away" does technically have one barre chord, an F Major, but it doesn't occur during a singing part, so that could also be skipped, I'd say.
- Ben Gibbard - Carolina
- Ben Gibbard - You Remind Me Of Home
- Bon Iver - Skinny Love
- Bruce Springsteen - Dancing In The Dark
- Jimmy Buffet - Margaritaville
- John Denver - Thank God I'm A Country Boy
- Kathleen Edwards - Asking For Flowers
- Kathleen Edwards - I Make The Dough, You Get The Glory
- Paul Simon - Slip Sliding Away
- Sufjan Stevens - Casimir Pulaski Day
- Sufjan Stevens - The Only Thing
- The Band - Atlantic City
- The Magnetic Fields - The Book Of Love
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