“art thou but / A dagger of the mind, a false creation, / Proceeding from the heat oppressèd brain?” (II.1.36-8). It is in this scene in which a dagger appears out of nowhere in front of Macbeth, after which he goes to kill his King, Duncan. Macbeth’s mind projects in front of him an imaginary dagger in order to prompt him to pull out his own dagger and do the killing that he dreads. We see, then, a kind of fracture, a peculiar autonomy of the mind that is able to take over the entire body and prompt it into action. Kevin Curran, as he traces the legal phenomenology in Macbeth, finds that “Thinking exceeds the boundaries of the purely physical or purely mental since it entails an act of quasi-physical mental acquisition, one that in this soliloquy is literalized when Macbeth reaches out for the mental dagger, eventually replacing it with his own real dagger” (395). Curran examines the way thinking is transformed into doing, a fact which places knowledge at the same level as action, specifically in this case when it comes to criminality: “Macbeth teaches us not only that power corrupts, but also that knowledge corrupts” (392). It is the knowledge planted by the Witches’ prophecy that initiates Macbeth’s corruption and plants in him criminal thoughts which later turn into criminal actions. By emphasizing Macbeth’s introspective nature, Shakespeare blurs the lines between criminal thought and criminal action. Macbeth lives in his own mind.

Curran, as does Wilson (see 455 & 477), traces in Macbeth a reliable source of human experience through which the psychology of crime might be understood. There is a legal phenomenology that can be traced in the play and which seems to uncover the significance of perception on criminal actions. Curran writes: “This legal phenomenology concedes that crime involves knowledge, but it insists that knowledge is always situated in a lived environment. It concedes that crime involves thinking, but it insists that one always thinks with things—with daggers, with pillows, with bodies” (396). Thinking is, therefore, made less abstract and more forceful; it is matter that takes over the body. The ideas, in Marleau-Ponte’s words, “come into being” (Curran, 398). Similar is Lady Macbeth’s plea to be “filled with direst cruelty”, to “Stop up the access and passage to remorse” (I.5.40-41). She understands that she must direct her mind to cruelty in order to act in cruelty.

In understanding the force of criminal thought in Macbeth, particularly in the way it results in criminal action, we are prompted to reassess the legal system’s approach to criminal thought in comparison to criminal action. Shakespeare in Macbeth shows that there is very little difference between thinking and acting—thinking is acting, the thought comes into being, manifests itself into something more concrete. Curran concludes “For scholars interested in literature and law, this approach to Macbeth offers new ways of thinking about law’s knowledge-making properties, since it puts the artistic rendering of criminality into conversation with systematic attempts to model human experience and consciousness in philosophy” (398). Shakespeare, in modeling human consciousness in his plays, becomes an important source of knowledge that can help shape legal epistemology.