Will Implementing Smart Contracts in Bitcoin Undermine Its Usefulness as Money ?

Swingle opened by explaining Bitcoin's monetary advantages. "The value proposition of bitcoin, for me, is that it combines the scarcity of a commodity like gold with the transactional efficiency of a purely-digital medium," he stated. "It makes it possible to store and transfer value, including across distance, without the need for a trusted central intermediary." Swingle emphasized that this capability addresses real-world needs—conventional monetary systems suffer from significant limitations affecting daily commerce. "From my perspective, conventional forms of money are all hugely flawed," he remarked. Bitcoin's utility extends across darknet markets, Wikileaks fundraising channels, and the burgeoning online gambling sector. Future potential includes micropayments, an area where traditional money has faltered.

Regarding smart contracts, Swingle expressed skepticism about their broad applicability. He defined them as "an agreement that is intended to be enforceable automatically via executable code" before examining whether they truly solve traditional contract problems. A fundamental contract issue involves parties believing they've reached consensus when fundamental disagreements persist. Smart contracts, however, don't address this challenge. "The aspects of a contract that actually lend themselves to expression in objective black and white code are not the aspects that are likely to raise confusion," Swingle observed. Average users struggle to comprehend what smart contract code actually executes, and code sometimes behaves differently than anticipated—The DAO exemplifying this hazard.

Traditional contracts also suffer from expensive, protracted litigation, compounded by potentially incompetent or dishonest adjudicators. Smart contracts still depend on external oracles confirming real-world circumstances, meaning parties must still prove their position to these intermediaries. "My suspicion is that losing big because of a bug is probably greater than the typical risk that you'll lose big to a judge that refuses to properly apply a truly unambiguous agreement," Swingle said. Since oracles face identical corruption and incompetence risks, this problem persists. "Smart contracts seem to help, but only via forced funds escrow because in order for the smart contract to enforce the payment obligation, the funds have to be encumbered and sort if put under the control of the contract," he explained. Ultimately, "Smart contracts aren't or don't seem to be a general solution to the problem of contracts; whereas, cryptocurrency arguably is a general solution to the entire problem of money . . . [Smart contract use cases] aren't really the pain point of contracts. In other words, it's like the least likely aspect of a contract to cause a problem."

Given smart contracts' limited practical value, Swingle advocates confining them to layers above Bitcoin's foundation. "We may not want this advanced smart contract functionality to live in the base protocol because it seems like you're potentially adding features to support a marginal use case at the potential expense of undermining the dominant and much, much more important use case," he explained. RSK, a Bitcoin sidechain enabling sophisticated smart contracting similar to Ethereum's model, demonstrates this layered approach—operating independently without disrupting the primary Bitcoin network. Bitcoin's previous additions—such as the OP_CSV opcode designed to enhance second-layer systems like the Lightning Network—followed this incremental, purpose-driven methodology.