>Intelligence, or how we would currently define it colloquially and imprecisely, is an algorithm or a class of algorithms with some specific capabilities.
To me it sounds like you are expanding inability to describe how intelligent things function into an inability to even describe intelligence. Intelligence as algorithm does not match with what I think are the best descriptions of intelligence.
Intelligence is an individual's ability to act towards achieving goals in uncertain environments.
How an individual functions: the way it acts, how it forms goals, how it models the environment. These will all determine how intelligent that individual is.
>The only kind of intelligence we know, our own, comes with a host of disadvantages that may be features of the particular algorithm employed by the brain and/or to limitations of the hardware, but they could possibly be essential to intelligence itself.
I think the idea that limitations to intelligence are inherent to intelligence itself is wrong. Not unsupported, but actually wrong.
>Even if a higher intelligence than humans' is possible, its hypothetical achievements are uncertain.
But you must admit more intelligent beings will certainly not have the same achievements as humans. What separates intelligent beings are the quality of outcomes. By being more intelligence they will have better outcomes.
Given the same constraints they will act more intelligently and achieve better outcomes. And we know machine intelligence will certainly be less constrained than ourselves. They will be able to directly self modify their intelligence, have infinite life spans, construct any sensors and actuators to expand input/output signals, determine their level of energy consumption, etc.
I don't see how anyone could not concede that machine intelligence will obviously be superior to human intelligence. The space of intelligence is so much larger than the point we occupy.