An agent exercises instrumental rationality to the degree that she adopts appropriate means to achieving her ends. Adopting appropriate means to achieving one’s ends can, in turn, involve overcoming one’s strongest desires, that is, it can involve exercising synchronic self-control. However, contra prominent approaches, I deny that synchronic self-control is possible. Specifically, I draw on computational models and empirical evidence from cognitive neuroscience to describe a naturalistic, multi-system model of the mind. On this model, synchronic self-control is impossible. Must we, then, give up on a meaningful conception of instrumental rationality? No. A multi-system view still permits something like synchronic self-control: an agent can control her very strong desires. Adopting a multi-system model of the mind thus places limitations on our conceptions of instrumental rationality, without requiring that we abandon the notion altogether.

代理人在采取适当的手段实现自己的目的的程度内，行使工具理性。反过来，采用适当的方法来达到自己的目的，可能会涉及克服一个人的最强烈的愿望，也就是说，它可能涉及行使同步的自我控制能力。但是，与其他突出的方法相反，我否认同步自我控制是可能的。具体来说，我利用认知神经科学的计算模型和经验证据来描述一种自然的，多系统的思维模型。在此模型上，同步自我控制是不可能的。那么，我们是否必须放弃有意义的工具理性概念？第一种多系统视图下仍然允许什么样时性自我控制：代理可以控制她非常强劲欲望。因此，采用思维的多系统模型会限制我们对工具理性的概念，而无需我们完全放弃这一概念。