Blockchain is not simply a database. A blockchain's smart contract is not simply a function.
From a human perspective, it is a neutral decision-making rule; from a hardware perspective, it is a control policy. The keywords "neutral," "decision-making," and "control" matter here, but more importantly, we should notice that humans and hardware are being placed on the same level of comparison.
In the past, in order for humans to move tools, it was accomplished through human hands or physical force. But as remote controls emerged, handles were created, and various buttons came to operate different functions.
If that is the hardware side, what about the software (or blockchain) side? In reality, the human hand that moves hardware is, in blockchain, the smart contract. The control here is not carried out by simple condition-matching or by the individual preferences and decisions of an operator or consumer. Just as a car's semiconductor does, just as a laptop's keyboard does, just as a smart key on a front door does, it moves only by a given policy (condition).
From this angle, the force that moves hardware can be summarized as labor and policy.
