Just as there are odors that dogs can smell and we cannot, as well as sounds that dogs can hear and we cannot, so too there are wavelengths of light we cannot see and flavors we cannot taste. Why then, given our brains wired the way they are, does the remark, "Perhaps there are thoughts we cannot think," surprise you?
In Pinker's book "How the Mind Works" he asks the same question. His observation (as I recall) was that much of our apparently abstract logical abilities are done by mapping abstractions like math onto evolved subsystems with different survival purposes in our ancestors: pattern recognition, 3D spatial visualization, etc. He suggests that some problems seem intractable because they don't map cleanly to any of those subsystems.
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