First, I ignored the Bitcoin block-size debate. It was always clear to me that we needed bigger blocks and the one MB limit is purely artificial. Historically, the block-size limit was introduced to make it impossible to spam-attack the network while bitcoins were cheap. Satoshi himself had no block-size limit. He was talking about '100 million transactions per day', which clearly need more space than one MB.
The main argument among those who reject a block-size increase is that Bitcoin would centralize even faster because the costs are rising of running a full node. This would make Bitcoin insecure.
This is wrong! Adding 1000 nodes randomly around the world would not increase Bitcoin's security.
Bitcoin's security is not a function of the number of nodes running around the world, but clearly a function of the decentralization of the miners. Mining via Proof-of-Work in Bitcoin exists specifically to create security by making it impossible for one entity to perform a sybil-attack and create several blocks after each other. Adding 1000 Miners at random locations around the world would increase the security.
Satoshi envisioned Simplified Payment Verification (SPV) in order to make it secure to use Bitcoin via a light client, i.e. not a full node. The light client can verify the work done by the miners and also verify that the transaction got included in a block.
Now, Bitcoin is hardly decentralized anymore! Most of the hash-power is located in China, which is under the sole rule of 'the party'. And China has a lot of reasons not to like BTC since it is the way to go to transfer money out of China, which is restricted.
Instead of debating Bitcoin into an early grave by continuing the block-size discussion, we should rapidly change the PoW algorithm to make it impossible to build custom ASIC hardware; making Satoshi's vision of One-CPU-One-Vote true again. Therefore, we need a dynamic PoW algorithm. Dynamic hashing could be one way. Another way could be finding a certain sequence of prime numbers, like in Primecoin — the "Cunningham-chain". Also the prime-number-chain algorithm needs to be dynamic, meaning that the requirements for the prime-number-chains need to change over time.
> Cunningham chains are also sometimes generalized to sequences of prime numbers (_p_1, …, pn) such that for all 1 ≤ i ≤ n, pi+1 = api + b for fixed coprime integers a, b; the resulting chains are called generalized Cunningham chains. — from Wikipedia
Why "Proof-of-Intelligence"?
While it is trivial to try to brute-force all prime numbers, nobody can write an efficient algorithm for finding all prime numbers. And one can't build hardware for it. One needs to use human brainpower to improve the algorithm. And everybody has a brain.
The question which remains is, whether it is possible to improve the algorithm by an order of magnitude.
Back to Bitcoin
If we don't want Bitcoin to be centralized further, we should start a discussion about changing the PoW-algorithm, and stop talking about the block-size. The change can be done in a smooth way, meaning that at the start we can require that every 16th block needs to be mined by this new algorithm. After a while every 8th, then 4th, 2nd and finally every single one. Let's discuss.