According to constructive empiricists, accepting a scientific theory involves belief only that it is true of the observable world, where observability is defined in terms of what is detectable by the unaided senses. On this view, scientific instruments are machines that generate new observable data, but this data need not be interpreted as providing access to a realm of phenomena beyond what is revealed by the senses. A recent challenge to the constructive empiricist account of instruments appeals to the extended mind thesis, according to which cognitive processes are sometimes constituted not just by brain activity, but can extend into the rest of the body and the surrounding environment. If this is right, scientific instruments may, in the right circumstances, literally become part of our perceptual processes. In this article, I examine this extended perception argument, and I find that it fails for the vast majority of scientific instruments. Even if the extended mind thesis is accepted, the constructive empiricist can draw a line between observables and unobservables that makes very few concessions to the realist.

根据建设性经验主义者的说法，接受一个科学理论只需要相信它对可观察的世界是正确的，其中可观察性是根据肉眼可检测到的东西来定义的。根据这种观点，科学仪器是产生新的可观察数据的机器，但这些数据不需要被解释为提供对超越感官所揭示的现象领域的访问。最近对工具的建设性经验主义解释提出的挑战诉诸扩展心智论题，根据该论点，认知过程有时不仅由大脑活动构成，而且可以延伸到身体的其他部分和周围环境。如果这是正确的，那么科学仪器在适当的情况下可能会真正成为我们感知过程的一部分。在本文中，我研究了这个扩展的感知论点，我发现它对绝大多数科学仪器都失败了。即使扩展思维论点被接受，建设性的经验主义者也可以在可观察的和不可观察的之间划出一条线，对现实主义者做出很少的让步。