By Karina Vold

In November 2017， a gunman entered a church in Sutherland Springs in Texas， where he killed 26 people and wounded 20 others. He escaped in his car， with police and residents in hot pursuit， before losing control of the vehicle and flipping it into a ditch. When the police got to the car， he was dead. The episode is horrifying enough without its unsettling epilogue.1 In the course of their investigations， the FBI reportedly pressed the gunmans finger to the fingerprint-recognition feature on his iPhone in an attempt to unlock it. Regardless of whos affected， its disquieting to think of the police using a corpse to break into someones digital afterlife.

Most democratic constitutions shield us from unwanted intrusions into our brains and bodies. They also enshrine2 our entitlement to freedom of thought and mental privacy. Thats why neurochemical drugs that interfere with cognitive functioning cant be administered against a persons will unless theres a clear medical justification. Similarly， according to scholarly opinion， law-enforcement officials cant compel someone to take a lie-detector test， because that would be an invasion of privacy and a violation of the right to remain silent.

But in the present era of ubiquitous technology， philosophers are beginning to ask whether biological anatomy really captures the entirety of who we are.3 Given the role they play in our lives， do our devices deserve the same protections as our brains and bodies？

After all， your smartphone is much more than just a phone. It can tell a more intimate story about you than your best friend. No other piece of hardware in history， not even your brain， contains the quality or quantity of information held on your phone： it “knows” whom you speak to， when you speak to them， what you said， where you have been， your purchases， photos， biometric4 data， even your notes to yourself—and all this dating back years.

In 2014， the United States Supreme Court used this observation to justify the decision that police must obtain a warrant before rummaging5 through our smartphones. These devices “are now such a pervasive and insistent part of daily life that the proverbial6 visitor from Mars might conclude they were an important feature of human anatomy”， as Chief Justice John Roberts observed in his written opinion.

The Chief Justice probably wasnt making a metaphysical7 point—but the philosophers Andy Clark and David Chalmers were when they argued in “The Extended Mind” （1998） that technology is actually part of us. According to traditional cognitive science， “thinking” is a process of symbol manipulation or neural computation， which gets carried out by the brain. Clark and Chalmers broadly accept this computational theory of mind， but claim that tools can become seamlessly8 integrated into how we think. Objects such as smartphones or notepads are often just as functionally essential to our cognition as the synapses9 firing in our heads. They augment10 and extend our minds by increasing our cognitive power and freeing up internal resources.

If accepted， the extended mind thesis threatens widespread cultural assumptions about the inviolate11 nature of thought， which sits at the heart of most legal and social norms. As the US Supreme Court declared in 1942： “freedom to think is absolute of its own nature； the most tyrannical12 government is powerless to control the inward workings of the mind.” This view has its origins in thinkers such as John Locke and René Descartes，13 who argued that the human soul is locked in a physical body， but that our thoughts exist in an immaterial world， inaccessible to other people. Ones inner life thus needs protecting only when it is externalised， such as through speech. Many researchers in cognitive science still cling to this Cartesian14 conception—only， now， the private realm of thought coincides with activity in the brain.

But todays legal institutions are straining15 against this narrow concept of the mind. They are trying to come to grips with how technology is changing what it means to be human， and to devise new normative16 boundaries to cope with this reality. Justice Roberts might not have known about the idea of the extended mind， but it supports his wry17 observation that smartphones have become part of our body. If our minds now encompass our phones， we are essentially cyborgs18： part-biology， part-technology. Given how our smartphones have taken over what were once functions of our brains—remembering dates， phone numbers， addresses—perhaps the data they contain should be treated on a par with19 the information we hold in our heads. So if the law aims to protect mental privacy， its boundaries would need to be pushed outwards to give our cyborg anatomy the same protections as our brains.

This line of reasoning leads to some potentially radical conclusions. Some philosophers have argued that when we die， our digital devices should be handled as remains： if your smartphone is a part of who you are， then perhaps it should be treated more like your corpse than your couch. Similarly， one might argue that trashing someones smartphone should be seen as a form of “extended” assault， equivalent to a blow to the head， rather than just destruction of property. If your memories are erased because someone attacks you with a club， a court would have no trouble characterising the episode as a violent incident. So if someone breaks your smartphone and wipes its contents， perhaps the perpetrator20 should be punished as they would be if they had caused a head trauma.

The extended mind thesis also challenges the laws role in protecting both the content and the means of thought—that is， shielding what and how we think from undue influence. Regulation bars non-consensual interference in our neurochemistry （for example， through drugs）， because that meddles with the contents of our mind.21 But if cognition encompasses devices， then arguably they should be subject to the same prohibitions. Perhaps some of the techniques that advertisers use to hijack our attention online， to nudge22 our decision-making or manipulate search results， should count as intrusions on our cognitive process. Similarly， in areas where the law protects the means of thought， it might need to guarantee access to tools such as smartphones—in the same way that freedom of expression protects peoples right not only to write or speak， but also to use computers and disseminate23 speech over the internet.

The courts are still some way from arriving at such decisions. Besides the headline-making cases of mass shooters， there are thousands of instances each year in which police authorities try to get access to encrypted24 devices. Although the Fifth Amendment to the US Constitution protects individuals right to remain silent（and therefore not give up a passcode）， judges in several states have ruled that police can forcibly use fingerprints to unlock a users phone. （With the new facial-recognition feature on the iPhone X， police might only need to get an unwitting25 user to look at her phone.） These decisions reflect the traditional concept that the rights and freedoms of an individual end at the skin.

But the concept of personal rights and freedoms that guides our legal institutions is outdated. It is built on a model of a free individual who enjoys an untouchable inner life. Now， though， our thoughts can be invaded before they have even been developed—and in a way， perhaps this is nothing new. The Nobel Prize-winning physicist Richard Feynman26 used to say that he thought with his notebook. Without a pen and pencil， a great deal of complex reflection and analysis would never have been possible. If the extended mind view is right， then even simple technologies such as these would merit recognition and protection as a part of the essential toolkit of the mind.

2017年11月，一名槍手闯入得克萨斯州萨瑟兰泉的一座教堂，造成26人死亡，20人受伤。他驾车逃离，警察和居民紧追不舍，结果汽车失控翻入沟中。警方赶到之时，枪手已经死亡。即使没有最后那个令人不安的结果，这个事件也已经足够可怕了。据报道，在调查过程中，FBI把枪手的手指按在他iPhone指纹识别的位置上试图解锁手机。且不论谁会受到影响，光是想到警察用尸体侵入某人死后的数码生命，就难免令人感到不安。

大多数民主宪法保护我们的大脑和身体不受侵犯。这些宪法也保障我们的思想自由和精神隐私神圣不可侵犯。这也就是为什么干扰认知功能的神经化学药物不能在违背当事人意志的情况下使用，除非有明确的医学理由。同样，根据学者的意见，执法人员不能强迫某人测谎，因为这会侵犯隐私权和保持沉默的权利。

但在这个技术无处不在的时代，哲学家们开始质疑生物解剖是否真能完整地捕捉到我们是谁。鉴于手机设备在我们生活中扮演的角色，我们的手机设备是否应该得到与我们的大脑和身体同等的保护？

毕竟，你的智能手机不仅仅是一部手机。它比你最好的朋友还了解更私密的那个你。历史上还没有哪种硬件，甚至包括你的大脑，能像手机那样包含如此质量或数量的信息：手机知道你和谁说话，何时说话，说了什么，去过哪里，你的购买记录、照片、生物识别数据，甚至是你写给自己的备忘录——而且还是过去数年来的所有这些信息。……