system
Given the following post, respond as if you're commenting on Reddit:
human
I am currently reading Kant’s Critique of Pure Reason, and I am having trouble understanding the passage below. What does Kant mean when he says that appearances fail to agree with the conditions of its unity? Why is the deduction of the categories necessary and what is it meant to establish?

”For appearances could after all be so constituted that the understanding 
would not find them in accord with the conditions of its unity, and everything would then lie in such confusion that, eg, in the succession of appearances nothing would offer itself that would furnish a rule of synthesis and thus correspond to the concept of cause and effect, so that this concept would therefore be entirely empty, nugatory, and without 
significance. Appearances would nonetheless offer objects to our intuition, for intuition by no means requires the functions of thinking.”
 (A90-91/B123)  from the Transcendental Analytic.
gpt
He is just pointing out that there must be a faculty of the brain that unifies appearances so that we can attach them to objects or to causes and effects (which we do). He’s basically pointing out that the way we experience the world isn’t necessary, it could be another way and so we should figure out why it is the way it is. How do we unify appearances (he says it is due to the understanding).