Is this a dagger, which I see before me,
The handle toward my hand? Come, let me clutch thee.
I have thee not, and yet I see thee still.
Art thou not fatal vision, sensible
To feeling as to sight? Or art thou but
A dagger of the mind
(Shakespeare, Macbeth 2.1.34–9)
 When Macbeth reaches towards the invisible dagger hovering before him, he clutches not only at a vision of his murder weapon, but at one of the problems underpinning the spectre’s entry into the visual realm. How is one to understand sensory information that is riven with contradiction? Forced to reconcile the visible appearance of the floating knife with his understanding of plausible daggerly behaviour, Macbeth rapidly persuades himself, ‘There’s no such thing, / It is the bloody business which informs / Thus to mine eyes’ (1998: 2.1.48–50). In this he is correct, insofar as the dagger does not appear to exist in the material plane outside of his perception. This does not resolve the problem, however, of what it is he sees. Lady Macbeth protests that it is an ‘air-drawn dagger’ that ‘would well become / A woman’s story at a winter’s fire’ – a popular reading of the matter, although a prejudiced one given her fear that Macbeth’s visions may sabotage her own ambitions (1998: 3.4.62–5). Typically, the play’s critics have concurred with her, presuming that the dagger is an illusion that Macbeth must overcome. For instance, Nicholas Brooke comments in his introduction to the Oxford World Classics edition that ‘even Macbeth knows it is not there,’ while in Shakespeare and Cognition, Arthur Kinney describes the dagger as a ‘self-acknowledged […] hallucination’ (Brook 1998: 4; Kinney 2006: 78). Macbeth’s response is considerably more clouded than such readings suggest though: his speculation that it might be a ‘false creation / Proceeding from the heat–oppressèd brain,’ is only one of several questions in which he endeavours to reconcile the evidence of his eyes with the conflicting evidence of his other senses (Shakespeare 1998: 2.1.39–40). Despite his best efforts, the vision persists — he subsequently complains, ‘I see thee still; / And on thy blade and dudgeon gouts of blood, / Which was not so before’ (1998: 2.1.46–8). It is only at this point that he attempts to regain control over his vision and asserts, somewhat unconvincingly, ‘There’s no such thing’ (1998: 2.1.48). It seems more accurate, therefore, to suggest that Macbeth’s only means to restore his courage is to persuade himself that there is no such thing, than to argue that he is wholeheartedly certain of it.
 The complexity and indeterminacy of Macbeth’s vision only becomes apparent when we begin to consider how early modern understandings of sensory perception inform and intersect with interpretations of the supernatural. While the bloody dagger lacks a tangible form, its perceived presence denotes a slippage between material ‘reality’ and the perception of that reality through the mechanism of vision: a problem that is particularly evident within early modern debates concerning the nature of apparitions. The dagger scene in Macbeth exemplifies a wider trend within the theatre — seized upon by Shakespeare, in particular — to exploit tensions and instabilities within theological, philosophical, and popular constructions of the ghost and associated visual phenomena. In Reformation England, the figure of the ghost had become a focal point for tensions between Protestant and Catholic accounts of the afterlife. In the medieval period, the interpretation of ghosts as spirits of the dead had been theologically plausible, with the concept of purgatory providing a staging point from which the dead might return. Such interpretations were effectively ruled invalid when the Church of England dispensed with purgatory in the early years of Elizabeth I’s reign; broadly speaking, the ghost had no logical home within the terms of the Protestant afterlife. In practice, however, both popular beliefs and theological perspectives remained diverse, and the figure of the ghost became less stable as it grew in significance. As Stuart Clark points out, this meant that the ghost’s ‘identification as visual phenomena’ became increasingly insecure (2003: 149). If the ability to identify the true nature of ghosts was crucial in determining questions of theological allegiance and therefore spiritual salvation, the interpretation of ghost sightings was all the more hazardous for it.
 As the multitude of ghosts within Elizabethan and early Jacobean theatre suggests, the problem of how to read the figure of the ghost was offering outstanding dramatic fodder. Nowhere is this more apparent than in Macbeth, Hamlet, and Julius Caesar, for in these plays Shakespeare’s treatment of the apparition problematises the nature of vision in such a way as to subvert radically the subject’s ability to comprehend the world accurately through the mechanism of the gaze. Each of the ghosts in these works refuses any clarification of the terms under which it appears, unsettling distinctions between reality and illusion, or the inner world of the subject and the objects that he perceives. The ghost becomes genuinely spectral, emerging within, between, and beyond the structures of visual perception and knowledge: and it invites us to look more closely, not just at the dead, but at the living, and the uncertain relation between the inner and outer worlds that they inhabit.
The Problem with Seeing Things
 The wider discursive context into which Shakespeare’s ghosts enter is one in which theologians and demonologists alike were addressing the figure of the ghost through ‘a common epistemology of the visual sense and its deceptions’ (Clark 2003: 147). This was by no means a new approach, although conceptions of vision were continuing to evolve; philosophers ranging from Aristotle and Plato to Saint Thomas Aquinas had prioritised the sight as a crucial sense in shaping knowledge, while implicitly problematizing the variable means by which specific visions are generated. Aquinas’s work was particularly significant, for he had suggested that visual perception might sometimes occur in response to stimulation of the imagination instead of an ‘external sensible object’ (Aquinas 1951: 227). He thereby evoked the possibility of slippage between the registering of images with an external origin and those that were produced purely imaginatively, as well as providing a rationale for the corruption of visual perception even where the physical sense was intact. For early modern scholars, such difficulties were crucial in the debate over how to read the figure of the ghost. The Protestant theologian Ludwig Lavater exemplifies this in his seminal tract Of Ghostes and Spirites Walking by Nyght, in which he seizes upon pre-established problems in the relationship between vision and perception as a means to dissuade the reader from any form of belief in ghosts. Drawing upon notions stemming back to Aristotle and even earlier, Lavater suggests that the susceptible include those who ‘are timorous,’ ‘drinke wine immoderately,’ are ‘Madde,’ ‘melancholic,’ or ‘weake of sight,’ and those, in particular, whose ‘feare and weaknesse of the syghte and of other sens[e]s méete togyther’. In every instance, he suggests, ‘the outward eyes […] can easily darken and dazell the inwarde sight of the mynde’ (Lavater 1572: 17, 13, 9, 16, 19, 141). It is not only the inner state that renders vision deceptive, however. For Lavater, there is also the ever-present possibility that fraudulent characters (typically priests and monks) may disguise themselves as apparitions to indoctrinate or defraud the gullible. At the other end of the spectrum, apparitions may be of a genuinely spiritual nature, whether good or evil. They may be divine visions, summoned by God to ‘stir men up from idlenesse and bring them to true repentaunce,’ ‘good Angels’ or spirits sent from God to help, or demonic spirits attempting to endanger the soul (Lavater 1572: 17, 159, 163). (Such ideas have a firm place within the popular imagination. Shakespeare draws upon precisely this when he has Hamlet worry that the devil may have taken on the shape of the ghost ‘Out of my weakness and my melancholy, / As he is very potent with such spirits’ (2006: 2.5.536–37).)
 Nevertheless, Lavater still suggests that ghosts are not always illusions, even where they cannot be accorded a spiritual source. The fact that an object is not haptically or epistemologically present in the material world — that its existence cannot be verified by touch or by existing categories of knowledge — does not automatically prohibit it from another, equally legitimate form of existence. Drawing on an assortment of classical, folk, and Christian narratives, Lavater provides numerous accounts in which supernatural phenomena appear to ‘men of good corage, and such as have bin perfectly in their wits’ (1572: 88). This often occurs before a violent event: for example, when ‘great stirrings or noises’ and ‘stra[n]ge things’ occur before upheavals within a nation. Visual phenomena include ‘swords, speares, and suche like’ that are sighted ‘in the aire’ and ‘Gunnes, launces and halberdes, with other kindes of weapons and artillerie’ that ‘move of their owne accord as they lye in the armories’ (1572: 77, 81). Considered in the context of such beliefs, Macbeth’s dagger clearly occupies a place that extends, at least potentially, beyond the sphere of pure hallucination. Since it is not only Macbeth who sees and hears supernatural phenomena — other characters also witness ‘Lamentings heard i’th’ air, strange screams of death,’ cannibalistic horses, and the turning of daytime to ‘darkness […] When living light should kiss it’ — Macbeth’s vision cannot be attributed to imagination alone (Shakespeare 1998: 2.3.57, 2.4.9–10). Instead, it exposes the problem of vision as a sense that disallows separation between interior and exterior ‘realities’ and draws us into the uncanny, the strange ‘commingling of the familiar and the unfamiliar’ that disrupts our sense of what is possible or ‘proper’ (Royle 2003: 1). What Macbeth sees cannot be trusted or verified, but nor can it be explained or dismissed. Seeing is not believing, but when faced with a spectre, neither is it meaningless nor even necessarily misleading.
 Macbeth therefore enacts one of Lavater’s central concerns, that vision is hazardous in its ability to impart certainty. In this opinion, Lavater is inadvertently endorsed by the French Catholic writer Pierre Le Loyer, whose text A Treatise of Specters functions as a rebuttal of Lavater’s work. In an attempt to provide a basis for legitimizing the ghost, Le Loyer addresses much more extensively the problems of vision as a means of measuring the nature and veracity of visual phenomena. He endeavours to taxonomize the nature of visual perceptions, producing a series of categorizations designed to guide spiritual understanding of such matters. It is a fraught endeavour and his categorizations are riven with inconsistencies and ambiguities. To begin with, Le Loyer outlines five forms of vision. He first identifies three types of vision within Saint Augustine’s teachings: physical vision, ‘which is done by the eyes of the body’; ‘Imagination,’ which occurs through ‘some divine and heavenly inspiration’; and ‘Intellectuall’ vision, which ‘is done onely in the understanding’. In addition, he adds two categories of his own — dream visions that occur during sleep or in a state ‘betweene sleeping and waking’ and spiritual visions produced through a direct encounter with God (as in the case of Moses) (Le Loyer 1605: Sig. [B2v]). Le Loyer then adds the category of ‘the Fantasie, which is […] an Imagination and impression of the Soule, of such formes and shapes as are knowne’ or that are ‘imagined’ or constructed based on information from others (1605: Sig. [B2v]). Later, he further complicates his taxonomy in order to address the potential falsity of vision, asserting that there are in fact ‘two sortes of Imagination, namely, one Intellectuall, and without corporall substance: The other sensible and corporall’ (1605: B3[r]). The latter raises the possibility of illusion, but also the supernatural. Relying upon sensory information rather than reason, this type of vision is either ‘false’ and arises from ‘the imaginative power corrupted’ or ‘the senses hurt and altred: or else it is true; and then it is that which we call a Specter’ (1605: Sig. B4[r]).
 Le Loyer’s framework functions as a means of navigating through the problems of aligning sensory information with received understandings to facilitate accurate classification of an apparition. The distinctions appear crucial in understanding and distinguishing between phenomenal experiences, thereby offering a kind of pseudo-scientific basis for Le Loyer’s wider argument against Lavater’s dismissal of ghosts. Physical sight is important here, but he spends substantially more time considering the mental construction of vision as the more complex and problematic mechanism. In Le Loyer’s view, whether a vision is generated through memory, imagination, or through a process of reception of information and subsequent intellectual construction, has no immediate bearing on the vision’s validity: it is more a methodological distinction than a register of veracity. Such distinctions are tenuous at best, though, and Le Loyer’s taxonomy collapses even in the process of its construction as he struggles to shore up the boundaries between the different categories. The complexity of the relationship between physical, intellectual, psychic, and spiritual forms of comprehension counteracts clear distinctions between the perceptions that they produce. In Le Loyer’s shifting schema of vision, Macbeth’s ‘dagger of the mind’ might equally belong to the categories of the Imagination or the Intellectual, and perhaps even to that of the dream state. It might be intellectually constructed and incorporeal, a corporeal vision arising from corrupted senses, or a corporeal vision that is a genuine manifestation of the supernatural. The complexity of the perceptual framework only magnifies the problem of measuring the nature or accuracy of a specific vision. As Clark observes, Le Loyer identifies ‘so many problems with what is supposed to be “the most excellent, lively, and active” sense’ that he ultimately renders it the least reliant of them all (2003: 153).
Re/flection and the spectre
 Le Loyer’s strained attempts to distinguish between psychological, material, and spiritual elements in the production of vision may seem to hold little epistemological value. However, in exposing the lack of direct correlation between the material existence of an object and the perception of an object, his work suggests a crucial reciprocity in the relation between the two. The more Le Loyer accounts for the different catalysts for a vision, the more it seems that a perceived object is at least partly a product of the subject’s gaze. Like the dagger in Macbeth, Le Loyer’s schema is suggestive of the principle of flection at work within the visual process. The term ‘flection’ evolved across the seventeenth century to indicate, amongst other things, ‘a turning of the eye in any direction’ an ‘alteration, change, modification,’ and ‘bending’ or ‘curvature,’ (OED ‘flection,’ def. 1.d, 2, 1.a). The first two of these definitions are now obsolete, but if re-assimilated into the action of gazing, suggest that the bending of the eye towards the object of vision might also imply the potential for some kind of transformation therein. It disturbs the assumption that the act of looking provides the gazer with a true and accurate image of an exterior object and opens up the possibility that the flexures involved in directing the gaze and receiving an image in return may also generate warp. Worse still, they may expose discontinuities and maladjustment already present within the relation between the gazing subject and the object, thereby threatening, by extension, the relation between the subject and the wider external world.
 This is why Macbeth’s vision of the dagger is often interpreted as a symptom of a greater disorder, whether by Lady Macbeth, who considers both the dagger and the subsequent sighting of Banquo’s ghost to be ‘the very painting of your fear,’ or by critics such as Kenneth Muir, who describes the vision as ‘clearly an hallucination’ (Shakespeare 1998: 3.4.61; Muir, 1981: 233). By invoking a psychological cause for what Macbeth sees, such readings suggest that vision may tell us more about the inner state of the subject than about the external world. More than that though, this reciprocity is indicative of a process of active reflection. Clark indicates that mirroring was strongly associated with the spectre in Renaissance Europe, to the point that the French scholar Jean Pena had ‘suggested that all apparitions and spectres could be attributed to the natural effects of mirrors’ (Clark 2003: 148). This claim, however, is curiously inscribed with the reverse reflection to that which it propounds: if mirroring calls the spectre into view, it is perhaps not always through deception within the light or the physical environment, but through another kind of ‘natural’ reflection, that of the gazing subject himself.
 Here, we may think of the ‘visor effect’ that Derrida describes in Specters of Marx. Derrida’s work in this text is, of course, concerned primarily with the hauntings of Marx and his legacy: but Derrida’s reading of Old Hamlet’s ghost as an instance of the spectral disturbance of historical, political, and indeed human boundaries has important implications for the spectre that is literalized through the form of the ghost. In particular, his conceptualization of the visor effect highlights the return of the gaze by the spectre and the disjuncture that characterises this event. In reference to Old Hamlet’s ghost, Derrida observes an effect in which ‘we do not see who looks at us.’ Rather, a ‘spectral someone other looks at us, we feel ourselves being looked at by it, outside of any synchrony, even before and beyond any look on our part, according to an absolute anteriority […] and asymmetry, according to an absolutely unmasterable disproportion’ (Derrida 2006: 6–7). The gaze is reversed but disrupted so that it prohibits a direct correlation between perception and knowledge. This is precisely the effect that the spectral dagger generates in Macbeth. To the extent that Macbeth looks at and perceives the dagger, the dagger anticipates him, exposing something (we are not sure what) about his inner state and his functioning within the world he is attempting to comprehend. If this seems an unusual observation to make about an inanimate object, it is because this is the one thing the dagger is not. Invisible to the watching audience, the dagger cannot be fixed as illusion or object but instead becomes the product and locus of a radical problematization of the nature of perception. In The Early Modern Corpse and Shakespeare’s Theatre, Zimmerman suggests that the dagger evokes ‘an eerie agency that is not included in the signified of its corporeal referent’ (the other dagger that Macbeth physically draws): ‘Macbeth reaches a breach between his two modes of seeing,’ (the evidence of his eyes and of his other senses), but in endeavouring to argue that ‘There’s no such thing’ he ‘locates the crux of his dilemma. There is no such thing as the imagined dagger, but it exists none the less in some frame of vision’ (Zimmerman 2007: 177). Its entry into his visual field is real and therefore problematizes the distinction between what is perceived and what is. The indeterminacy of the object shows that visual perception functions as a register of the perceiver as much as of the external world, but refuses a clear correlation between the two so that neither functions simply as a reflection of the other’s state.
 In this respect, the dagger episode is a duplicate of the banquet scene in which Macbeth is the only one able to see Banquo’s ghost. The ghost’s appearance functions at once as the cause, reification, and reflection of his worsening psychological state. That Macbeth sees the ghost is indisputable: what it means that he sees the ghost is impossible to determine. Stephen Greenblatt claims that there are ‘two starkly conflicting possibilities: either the apparition is something real in the universe of the play — the spirit of the murdered Banquo […] or it is the hallucinatory production of Macbeth’s inward terror’ (2001: 190–91). However, the crux of the problem is that the play does not allow any polarisation of possibilities at all. Instead, it problematizes the nature of perception to the extent that almost any configuration of the relation between the watcher and the spectre is possible and therefore none can be settled upon.
 One of the problems that Macbeth faces, of course, is that in both incidents he is alone in his perception of the spectre. This is a problem that faces Hamlet also; however, in Hamlet, the audience is presented with an additional complication as the ghost’s visibility to onlookers shifts. It has attracted much critical comment that Old Hamlet’s ghost, initially witnessed by Barnardo, Marcellus, and Horatio as well as Hamlet, is visible to Hamlet alone when it enters Gertrude’s closet. In response to Hamlet’s question as to whether she sees nothing, Gertrude replies: ‘Nothing at all, yet all that is I see’ (2006: 3.4.129). Greenblatt, who construes the ghost as one of Hamlet’s ‘memory traces,’ comments that ‘Gertrude sees and hears nothing or, rather, more devastatingly, she sees and hears what exists’ (2001: 225). Yet her failure to see the ghost cannot firmly signal anything of the sort, given the popular Elizabethan belief that ghosts are not always visible to everyone in their presence. Scott Huelin argues more persuasively that the ghost may be the product of ‘Hamlet’s brain and yet […] not a hallucination, a manifest psychotic break.’ He points out that ‘one of the key experiences within meditative piety is […] the memorial phantasm, the image that appears before the mind’s eye unbidden yet prompted by sensory or intellectual stimuli’ (2005: 39). Huelin’s point usefully gestures towards a reciprocity between the image and the gazing subject. We can see this effect compounded by the stage direction that requires the ghost to appear onstage so that, whilst Gertrude cannot see the ghost, the audience can. With the ghost visibly present before our own eyes and audibly issuing Hamlet with instructions, we might as well question Gertrude’s powers of perception as those of Hamlet. The nature of the returned image is as dependent upon the position and inner state of the gazer as it is upon the object of perception.
 Episodes such as this demonstrate that the relation of the spectre to the visual plane is a crucial element in its spectrality. This is not to suggest that a spectre is only a spectre if it is visible, but rather that the visible spectre’s function is not extraneous to its visibility: that is to say, its visibility is not coincidental to, or isolable from, that which renders it spectral. Of course, this is true generally because spectrality is not something that claims an independent or material existence in the first instance but instead takes up a position within and between the structures of human knowledge and therefore perception. But it is also to do with a more specific relation between the gazing subject and the apparition. The process of flection means that the gaze is often transformative — that the image returned in response to the gaze is not a register of the material ‘reality’ of the object but rather of the object in relation to the subject’s perception. It follows that the emergence of spectrality within the image is indicative of a specific kind of relation between what governs and generates perception (the inner ‘being’) and the apparition or object. In particular, it suggests that where the apparition enters the uncanny, where it becomes truly spectral, is in the process of reflection.
 The spectre renders visible that which cannot or should not ordinarily be seen. This is not just the case in terms of the way in which it breaches our understanding of the material world of objects but, more specifically, in its capacity to expose visibly that which has no place within the visual realm and in so doing to render it uncanny. Freud expresses surprise (although not disagreement) at Schelling’s description of the uncanny as that which ‘ought to have remained secret and hidden but has come to light’ (Freud 1955: 225). In terms of the spectre, though, this conception is particularly apposite: the word itself is contingent upon the notion of drawing forth and illuminating that which is not ordinarily subject to visibility. The OED’s definitions for the spectre include ‘an unreal object of thought; a phantasm of the brain,’ ‘an object or source of dread or terror, imagined as an apparition,’ and ‘an image or phantom produced by reflection or other natural cause,’ (OED ‘spectre,’ def. 1, 3). All three definitions are closely related. In having no identifiable locus within the physical realm — no objective, material presence — the spectre must be in some way a product of thought or imagination. Yet, if it is seen, the spectre is real, insofar as it is a genuine object of perception. In its incorporeality, it testifies to the existence of something that is disturbingly both perceptible and incomprehensible: it functions as a mirror for the gazing subject, returning the gaze of its audience in an act of re-flection.
 Derrida’s outline of the spectre’s visibility is particularly helpful here:
the specter, as its name indicates, is the frequency of a certain visibility. But the visibility of the invisible. And visibility, by its essence, is not seen, which is why it remains epekeina tes ousias, beyond the phenomenon or beyond being. The specter is also, among other things, what one imagines, what one thinks one sees and which one projects — on an imaginary screen where there is nothing to see. Not even the screen sometimes, and a screen always has, at bottom, in the bottom or background that it is, a structure of disappearing apparition. But now one can no longer get any shut–eye, being so intent to watch out for the return […] The perspective has to be reversed, once again: ghost or revenant, sensuous-non-sensuous, visible-invisible, the specter first of all sees us. (2006: 125)
Derrida’s deployment of the term ‘frequency’ draws the usually auditory conception of the nature or pitch of a sensory experience into the visual arena, so that it invokes not only recurrence but also the idea that the visibility of the spectre occurs at a particular ‘wavelength’. It suggests that the spectre becomes visible at the point that specular conditions propel it into the requisite frequency, rather than functioning as a marker of some kind of ontological movement of the spectre entering into ‘being.’ At the same time, the spectre is that which occurs where vision exceeds being, arising in the absence of any known phenomena. It thereby destroys any fixed correlation between phenomenal existence and visual perception. It exposes the fact that what is seen (the object) and what is (the gazing subject) are neither unrelated nor systematically linked, but function within an interdependent and shifting relation with one another that troubles the very basis of comprehension. The act of looking does not return information about the outer world alone, but also an ungraspable reflection of the inner subject who gazes. The sense of the ‘disappearing apparition,’ the spectre that must always return and for which one must always watch, is that which paradoxically eludes the gaze and yet also returns it.
 Thus, the relation between the subject and the spectre invokes and simultaneously disrupts the principles of reflection. Of the definitions listed in the OED, the following are particularly significant here:
2.a. Chiefly Anat. and Med. The action of bending, turning, or folding back, recurvation; a state of being bent or folded back…
c. The action of turning back from a point; return, retrogression…
3.a. The action of a mirror or other smooth or polished surface in reflecting an image; the fact or phenomenon of an image being produced in this way…
b. An image produced by or seen in a reflective surface, esp. a person’s image in a mirror…
c. fig. and in extended use. A depiction or reproduction…an embodiment.
In all of these conceptualizations, reflection is predicated upon the opposition of two terms, assuming an originary source and a secondary reflection. In the first two definitions, there is a non-specific return of an object that, in order to be ‘folded back’ or turned, relies upon the assumption of an originary movement that was in some sense straight or linear. In the following two, an independent object is duplicated as an image via the reflective surface of the mirror in a process that is specific to the act of perception: the eye of the subject gazing into the mirror is turned back towards itself, producing the simultaneous reversal of the gaze as well as a visual duplication of the original. This process is implicit also in the last definition, which, in referring to a secondary ‘reproduction’ or re-presentation, assumes the prior existence of an original. Taking these various manifestations together, reflection implies a recurrence or reversal, or a potential restoration of the seemingly originary state of flection. This process offers an enticing and duplicitous promise of truth, providing entry into a seemingly contained system of signification that promises to yield a one-to-one correlation between what is and what is reflected.
 In functioning thus, the mirror appears to be a perfectly positioned, flat surface in which the source is reflected without distortion. However, this ideal is itself illusory, for the reflection is dependent upon the gaze, the positioning of the gazing subject in relation to the mirror, the variable process of perception, and the integrity of the mirror itself. The image returned is infinitely variable in accordance with these factors. Hence, the reflection may be duplicitous in two senses, in its production of a double and in its potential to dupe. This is evident in both Macbeth and Hamlet where the principal characters each encounter ghosts that seem to reflect their disordered states and to deceive them as to the reality of the worlds that they inhabit. It is most explicit, though, in Julius Caesar. When Cassius asks Brutus whether he can see his own face, Brutus responds in the negative: ‘No, Cassius; / For the eye sees not itself / But by reflection, by some other things’ (2008: 1.2.52–53). Brutus appears to differentiate between self and reflection, suggesting that they are not synonymous. However, Cassius insists that Brutus merely needs to choose the proper mirror:
since you know you cannot see your self
So well as by reflection, I, your glass,
Will modestly discover to your self
That of yourself which you yet know not of.
(Shakespeare 2008: 1.2.67–70)
Colbert Kearney suggests that, in positioning himself as Brutus’s mirror, Cassius — who is ‘envious of Caesar’ — reflects a potentially matching envy in Brutus (1974: 145).We might add to this that Cassius has already inadvertently exposed the hidden danger of the mirror through his lament that Brutus has hitherto had ‘no such mirrors as will turn / Your hidden worthiness into your eye, / That you might see your shadow’ (Shakespeare 2008: 1.2.56–8).
 By the late sixteenth century, the term ‘shadow’ had a whole host of significations, including ‘the dark figure’ produced on a surface when a body intercepts the light; something that is ‘fleeting or ephemeral’; something that has ‘an unreal appearance; a delusive semblance or image’; ‘a spectral form’ or ‘phantom,’ and ‘one that constantly accompanies or follows another like a shadow’ (OED ‘shadow,’ def. 4.a, 4.c, 6.a, 7, 8). It is worth noting that the first of these definitions includes the additional qualifier that the shadowy image of the ‘intercepting body’ may be ‘approximately exact or more or less distorted’: this quality is precisely what manifests itself within the instability of Cassius’s choice of word. Whilst Cassius insists that his accurate mirroring will expose Brutus’s ‘hidden worthiness’ to himself, his choice of language suggests a host of other qualities it may simultaneously reveal, foreshadowing the darkness and treachery that see Brutus betray and murder Caesar. This last signification of shadowing or following a person has particular resonance here, for Brutus can no more escape his role as Caesar’s follower after the murder than he could before. After the death, he is still forced to present himself to Antony as ‘I, that did love Caesar’; he must grant Caesar proper burial rites because ‘It shall advantage more than do us wrong’; he finds it necessary to follow Caesar’s ghost to Philippi (Shakespeare 2008: 3.1.181; 3.1.242). His political position, his understanding of his own behaviour, and his course of action remain dependent upon Caesar even in death.
 The mirror, in this instance, exposes more than what the gazing subject wishes to see: but crucially, what it exposes is dependent upon the positioning of the gazing subject, for if Brutus’s ‘mirror’ exposes such darkness, its reflection fails to be received thus by Brutus himself. When Brutus subsequently encounters Caesar’s ghost, he might initially blame the vision upon ‘the weakness of mine eyes’, but the spectre clearly identifies itself as a more accurate reflection than that produced by Cassius (2008: 3.126):
Brutus. Art thou any thing?
Art thou some god, some angel, or some devil,
That mak’st my blood cold, and my hair to stare?
Speak to me what thou art.
Ghost. Thy evil spirit, Brutus
Kearney identifies the last line of this passage as the ghost ‘identifying itself as Brutus’ evil spirit’. That is to say, it functions as a mirror in which Brutus recognises ‘the Caesar in himself’ (Kearney 1974: 150). For Kearney, this complicates the ‘hallucination’ to provide an ‘insight into Brutus’s own character’ as he ‘confront[s] the Caesar, the autocrat, in his own psyche.’ Brutus now becomes ‘doomed by such self-destructive knowledge’ and proceeds rapidly towards securing his own death (1974: 150). Thus, the spectre functions as both product and reflection of Brutus’s tarnished soul. I would argue, however, that this psychological effect is not separable or distinct from the implication that the ghost is also ‘Thy evil spirit’ because it is the spirit that has been rendered a ghost at Brutus’s hands. It is not only an outward, embodied projection of an inner state, but equally an outer phenomenon — visible, after all, to the audience as well as to Brutus — that troubles the distinction between the two. By turning the process of re/flection into one of mediation, it refuses the originary structures that would see Brutus’s inner being functioning as the source of both flection and reflection. Instead, it inscribes the image of each within the other, so that the ghostly image is as much generative of Brutus’s inner self as it is reflective of it. If ‘the specter first of all sees us,’ it does not do so in the sense that it somehow captures an originary or pre-existing interior state of existence, but rather turns the act of perception into a fleeting glimpse of the shifting relation between inner and outer constructions (Derrida 2006: 125).
 It is important to acknowledge here that, although Shakespeare follows his historical source closely, his adaptation of his predecessor plays an essential part in heightening the uncanniness of the interaction between the two figures. Catherine Belsey notes that ‘the eeriness’ of Caesar’s ghost cannot simply be traced back to North’s English translation of Plutarch, from which Shakespeare draws. She points out that ‘in North’s version, as the lamp burns dim, a horrible figure is seen’ that terrifies Brutus, but once he realises it will not harm him, he moves to interrogate the ghost. As a result, ‘the fear and the question are divided’. However, Shakespeare instead draws the two ‘together, so that the fear is brought into being by the unknown’ — by Caesar’s inability to identify the apparition so that it ‘challenges the limits of mortal knowledge’ (Belsey 2010: 7). I would add that this effect is amplified as Shakespeare draws the ghost into a context that is specific to Elizabethan epistemology (and its limits). In North’s translation of ‘The Life of Brutus,’ Brutus asks the ghost whether he is ‘a god, or a man, and what cause brought him thither.’ The ghost then replies: ‘I am thy evill spirit, Brutus: and thou shalt see me by the citie of PHILIPPES’ (1579: 1072). The ghost appears when Brutus is awake, and disappears after he responds to its promise to appear in Philippi with the comment that he will see it there. The differences between Shakespeare’s and Plutarch’s versions are small, but significant. Shakespeare’s adaptation utilizes the language of Elizabethan demonology and theology so that Brutus expresses the typically Protestant polarization of spirits, modified according to its classical context: if it is ‘any thing,’ the ghost is either entirely good (‘some god, some angel’) or entirely evil (‘some devil’) — and yet we cannot be sure that it is ‘any thing’ at all. It therefore corrodes the ontological frameworks upon which Brutus draws as he attempts to comprehend the ghost’s presence. Despite his fear, Brutus is anxious to get more out of the ghost. After its announcement that he will see it at Philippi, he presses it further, asking ‘Well; then I shall see there again?’ Receiving an affirmative reply — ‘Ay, at Philippi — he then repeats the response described by Plutarch, ‘Why, I will see thee at Philippi then’ (Shakespeare 2008: 4.2.334–36). Shakespeare’s version of the scene thereby functions as a necessary narrative precursor to the meeting at Philippi, but the relation between the two figures becomes the crux of the encounter.
 This reimagining of the ghost’s appearance enables the perfusion of the boundaries between ghost and man and gives Brutus’s ‘evil spirit’ a markedly unsettling effect.Caesar’s ghost renders visible that which Cassius’s mirror does not. It reflects something within that he cannot and does not wish to see. And if he cannot grasp what it is that stands before him, nor can he willingly dismiss it: ‘Now I have taken heart thou vanishest,’ he complains, ‘Ill Spirit, I would hold more talk with thee’ (Shakespeare 2008: 4.2.337–38). Brutus seeks to render the ghost static and conjure it away — to banish its spectral threat — by affixing its position and extracting information from it. Unsuccessful, he cannot leave the matter alone. Functioning precisely within Derrida’s outline of the relation between spectator and apparition, Brutus is literally unable to ‘get any shut-eye’ because he is ‘intent to watch out for the return’ (Derrida 2006: 125). Late though it is, he rushes out to wake Lucius, Varro, and Claudius to check as to whether they saw anything, as though obtaining a secondary account of the ghost might enable him to obtain the ghost’s return by proxy. Failing to achieve this, he resorts to calling for Cassius to agree to set out immediately for Philippi. But even at Philippi, his final moments remain haunted by the ghost’s reflection. Faced with imminent capture and contemplating suicide, Brutus reveals that ‘The ghost of Caesar hath appeared to me / Two several times by night’ so that ‘I know my hour is come’ (Shakespeare 2008: 5.5.17–20). The desire for a noble death is therefore permeated by the preceding justification in which the ghost’s presence functions as the principal determinant of death. Similarly, his subsequent claim that ‘My heart doth joy that yet in all my life / I found no man but he was true to me’ registers that the ghost’s existence is attributable to his own failure to provide precisely that loyalty to Caesar (2008: 5.5.34–5). With this in mind, his final words — ‘Caesar, now be still. / I killed not thee with half so good a will’ — speaks not only of his apparent embrace of his own death but also of the perpetuation of Caesar’s presence within his final act (2008: 5.5.51–2).Brutus may consciously believe that he is obtaining ‘glory by this losing day’ but that which Caesar’s ghost reflects — Brutus’s moral weakness, his disregard for human life, his inner darkness — is literalized through his physical self-destruction (2008: 5.5.36).
 Here, reflection enters into psychoanalytic paradigms of the double’s place within the uncanny. The uncanny double replicates a familiar originary form in a way that denies the containment and unity of that form and thereby destabilizes its seeming independence. This destabilization begins within the revelation that what lies on one side of the imagined divide must be somehow be present within the other. In its most extreme forms, the double not only duplicates but even usurps the source, thereby dismantling the former hierarchy between the two (an event particularly popular within later forms of Gothic literature). For Freud, the double relation ‘is marked by the fact that the subject identifies himself with someone else, so that he is in doubt as to which his self is, or substitutes the extraneous self for his own. In other words, there is a doubling, dividing and interchanging of the self’ (1955: 234). The persistent reflection of Caesar’s presence within Brutus’s inner life invokes this type of relation, aided in part by the absence of clarity as to the ontological status of Caesar’s ghost. Put simply, we cannot quite tell where or if a boundary exists between the inner world of Brutus and the apparition of Caesar; although nor can we conclude that they are identical or continuous. Something that should remain hidden has become visible within Caesar’s ghost and Brutus alike, but it is something that we cannot grasp, for at every turn it disappears as readily as the ghost itself.
Visibility and the returned gaze
 It seems clear that Shakespeare’s ghosts haunt the individuals who most closely perceive them — that their haunting is contingent upon a certain engagement with the gazing subject. To be more precise, the ghost’s visibility and indeed its existence appears proportionate to the extent to which it anticipates, inhabits, and disrupts its audience’s understanding. A distinction (however unsettled) may be made between different levels of spectral visibility that are correlative to the degree to which the visor effect is at work. As Derrida’s focus upon Hamlet suggests, this is particularly clear within the contrasting experiences of Old Hamlet’s onlookers. In Hamlet,Marcellus, Barnardo, and Horatio all see Old Hamlet’s ghost and are transfixed by its appearance. They cannot dismiss it even after its departure and, although Horatio justifies his desire to advise Hamlet of the ghost’s appearance by claiming that it is ‘fitting our duty,’ his real motivation is to find a means to extract information from the ghost, and affix its meaning. If the ghost will not speak to them, he is certain that it will ‘speak to him,’ Hamlet (2006: 1.1.170–72). Yet Marcellus, Barnardo, and Horatio do not go mad or become obsessed by the ghost because, although the ghost sees them — it sees them fail to grasp or conceptualize its appearance, their inability to align their visual perception with their understanding of past and present — it does not see them in the same way that it sees Hamlet. It does not reflect back to them an interior disunity in the same way that it reflects this to Hamlet because Hamlet is the one whose inner state, familial relationships, and inheritance are inextricable from Old Hamlet’s death and who therefore enters a state of radical maladjustment in response to its return. Whilst the three original viewers are sufficiently disturbed by the ghost to anticipate its return and pursue an encounter through Hamlet that would ascribe it a meaning, it is for Hamlet that the ghost’s spectrality escalates into a full-scale corrosion of his ability to comprehend the structures of the world that he inhabits.
 For Hamlet, though, there is a reward to be found in the presence of the spectre that runs counter to its threat. In response to Horatio’s report of the ghost, Hamlet proceeds to question him by running through a catalogue of the ghost’s physical attributes:
Ham. Armed, say you?
Hor., Marc., Barn. Armed, my lord.
Ham. From top to toe?
Hor., Marc., Barn. My lord, from head to foot.
Ham. Then saw you not his face.
Hor. O yes my lord, he wore his beaver up.
Ham. What looked he – frowningly?
Hor. A countenance more in sorrow than in anger.
Ham. Pale, or red?
Hor. Nay very pale.
Ham. And fixed his eyes upon you?
Hor. Most constantly.
Ham. I would I had been there.
(Shakespeare 2006: 1.2.225–33)
Derrida comments that in the process of running through this list, it appears as though Hamlet ‘had been hoping that, beneath an armor that hides and protects from head to foot, the ghost would have shown neither his face, nor his look, nor therefore his identity’ (Derrida 2006: 8). However, I would argue that Hamlet’s desire to have been there to see the ghost himself, (reinforced by his declaration that he must lie in wait to see it himself), suggests otherwise. What Hamlet really seeks is for the ghost to fix its eyes upon him, even if ‘the helmet effect’ or ‘visor effect’ cannot be suspended. Hamlet rushes to see that which might expose to him the form of the father he has not yet finished mourning — however elusive it may be —and finds a clear but impenetrable connection between the independent existence of this spiritual entity and his melancholic attachment to his dead father.
 When he finally meets the ghost, Hamlet immediately addresses the spectre to demand the meaning of its ‘questionable shape’ (Shakespeare 2006: 1.4.43). In so doing, what he finds is not his father, but a reflection that far exceeds the constraints of origin and secondary term. In this vision that reifies hidden truths, Hamlet sees the affirmation of his own dis-order — an affirmation that liberates him by endorsing his inability to accept his father’s death and simultaneously binds him to a quest that can only secure his demise. Immediately before hearing news of the ghost, he tells Horatio ‘methinks I see my father’ and, when questioned as to where, responds ‘In my mind’s eye’ (2006: 1.2.183–84). In his mind’s eye — he sees the figure in the imaginative field of vision that knits memory with visual perception, a form of vision that is most subject to distortion, deception or illusion. Yet somehow, prior to any event of physical sight, he accurately perceives the continued presence of the figure that is walking the night.
 Spectrality in this sense extends far beyond the mere disturbance of the dead by the figure of the ghost: indeed, the spectre need not involve a ‘real’ ghost at all. If we turn once more to Macbeth, we can observe that its protagonist experiences a similarly disruptive encounter with the haunted reflection within the dumb show. William Engel suggests in Death and Drama in Renaissance England that dumb shows carry an association with ‘magical knowledge’ and the ‘occult arts,’ with the spectacle onstage holding ‘a mirror up to nature’ that helps to provide clarification in order to combat the deficiencies of sight. Thus, dumb shows ‘are like miniature mirrors within the larger mirror of the play,’ that also extend past ‘the contours of the main spectacle’ (Engel 2002: 42). In Macbeth, this effect extends to mirroring of the gaze along with its defects, exposing the disjuncture between what the audience sees and what it comprehends by turning spectacle into the spectral. In response to Macbeth’s question, ‘shall Banquo’s issue ever / Reign in this kingdom?’, the Weird Sisters respond with a silent procession of eight Scottish kings, tailed by the figure of the dead Banquo (Shakespeare 1998: 4.1.117–18). Although Macbeth finds the entire show unsettling because of the threat it signals to his ambitions, it is Banquo’s form at the end of the procession that seems to expose to him something formerly hidden from view: ‘Horrible sight — now I see ’tis true, / For the blood-baltered Banquo smiles upon me, / And points at them for his’ (1998: 4.1.137–39). Although this figure is not, apparently, Banquo’s ghost — it is ‘like the spirit of Banquo’ but not the spirit itself — this only amplifies its displacement of Banquo’s identity and the corresponding corruption of Macbeth’s perception (1998: 4.1.127). The ghost of a ghost, this figure’s inseparability from the mortal Banquo (whether living or dead), only further serves to heighten the disjunctures that render authoritative perception of the material world impossible. Like the ghost at the banquet table, it returns Macbeth’s gaze, reflecting back not only the horror of his past actions, but the future as well, a future that has already come back to haunt him. Macbeth’s subsequent response, ‘Let this pernicious hour / Stand aye accursèd in the calender,’ only serves as a stark reminder of just how little of his world now adheres to the ‘calender’ as the uncanniness of events exposes the interdependency of external world and the disorder of his inner being (1998: 4.1.148–49).
 When we examine the relation between viewer and spectre in this light, it becomes evident that the inner disruption generated under the returned gaze of the spectre is as much a formative aspect of spectrality as the visual apparition itself. Indeed, it is a key reason as to why there is always a distinction between the spectre of an object and one of the human form in terms of the effects they generate. If we turn again to Macbeth’s vision of the dagger, we might recall that it returns Macbeth’s gaze in the sense that it holds up a mirror to his inability to impose order upon inner or outer states or the alignment between the two. The floating dagger illuminates Macbeth’s impending murder of Duncan and metaphorizes the unnaturalness of his actions but also exposes the fact that time is failing to function in accordance with a linear ordering of events — for if the murder is yet to occur, even the image of the blood-soaked dagger has no place in the present. Despite his terror, though, Macbeth is much quicker to gather his wits and attempt to dismiss his vision of the dagger — which cannot literally cast a gaze — than he is when faced with his later vision of Banquo’s ghost. Where he is able to struggle through to the assertion that ‘There’s no such thing’ when faced with the dagger, he does not even begin to question the existence of Banquo’s ghost until after he has successfully persuaded it to depart and even then makes no firm pronouncements as to the veracity (or otherwise) of its existence (1998: 3.136). Whilst the audience may find the ghost more persuasive because it visibly sits onstage, we should remember that Macbeth has no such advantage: in both scenes, he alone is faced with the vision.
 This does not really appear to reflect a greater credibility in the ghost’s appearance, for example, in terms of being able to position it within a recognizable theological or mythological framework. Macbeth shows no sign of perceiving Banquo to have returned from a space such as the Catholic purgatory or classical underworld. Were it present, such a context might render the ghost less disturbing by ascribing it a logical, if not a comfortable presence. Instead, his complaint that ‘The times has been, / That when the brains were out the man would die, / And there an end; but now they rise again’ suggests quite the reverse. ‘Blood hath been shed […] murders have been performed’ both before and since legal intervention by ‘human statute,’ yet it is only now that men are failing to stay buried (1998: 3.4.76–81). Historically, as well as in the immediate context of the banquet hall, Macbeth perceives himself to be alone in his relation with the ambulatory dead. Banquo’s ghost has a place within physical or spiritual ‘reality’ that is neither more or less credible (or verifiable) than the vision of the dagger.
 What renders Banquo’s apparition more startling than the dagger, then, is that, as the returned dead, the ghost has a substantially more intrusive effect upon Macbeth’s psyche. It is not necessarily disruptive that a ghost is in the room: Banquo’s revenant troubles no-one at the banquet table other than Macbeth, just as Old Hamlet’s ghost does not directly trouble the unsuspecting Gertrude. By definition, one has to perceive a spectre for it to be rendered spectral, to perceive and thereby enter into the ruptures and unease that its presence generates and reflects. More problematically though, it is the dead — and therefore death — that Macbeth perceives. It is visible and yet not quite there; beyond his comprehension and yet clearly comprehending him. In failing to remain buried, static, and contained, the figure of Banquo refuses to allow Macbeth to insulate himself from death and move on with the business of living. Macbeth’s response to his vision demonstrates that what enables death not only to make itself felt but to resonate, to invade the very interior of the watching subject, is the way in which the entry of the ghost into the visual field establishes an unwelcome reflection of its observers. This problem registers itself within Macbeth’s curious phrasing: ‘they rise again’ to ‘push us from our stools’ (1998: 3.4.81–3, my emphasis). The ‘us’ here is not indicative of the majestic plural because the entire complaint is framed in the plural even though it is Banquo’s solitary ghost that plagues him, murdered only once and occupying only one stool. Macbeth’s phrasing not only reverses the roles of victim and murderer to redraw them as the dead usurper and the living victim but also positions them within a kind of reciprocal relation that exceeds the bounds of their individual positions. Unable to cope with the ramifications of Banquo’s return, Macbeth clutches at the one shred of reassurance that he can find, by extending the individual threat of the ghost to a universal one. Fear loves company, or at least so he hopes. It is, of course, to no avail, since his companions are oblivious to the spectre in the room. It is Macbeth alone who is unable to perceive Banquo to be at rest and it is Macbeth alone whose inner world begins to crumble beneath the force of the ghost’s stare. When the apparition takes up a place within Macbeth’s line of visual perception and then returns his gaze, it exposes to him his inability to isolate and preserve his interior self from the chaos of the exterior world because it attests to the instability of his self’s positioning, in time, in space, even in the line of political inheritance.
 Like the ghosts in Hamlet and Julius Caesar, then, the spectres in Macbeth manifest the profound complexity and instability in the complex relation between reality and perception. At a point in the early modern period when cultural and theological imperatives increasingly work to circumscribe and control the figure of the ghost, Shakespeare’s exploitation of the problems of visual perception magnifies the elusiveness and inconsistencies associated with the ghost’s appearance. Macbeth’s response to the dagger hinges upon his understanding that vision is key in comprehending the external world; yet it is precisely this that renders the spectre so disruptive. It threatens the subject’s ability to acquire accurate information through the physical senses, information that is crucial to issues, not only of life, but also of death and the afterlife. More dangerously still, it threatens to expose the fact that the external world is not fixed at all, but emerges through a shifting and reflexive relation with the gazing subject. This kind of haunting suggests that the unstable structures that enable visual perception paradoxically constitute both the apparatus through which the individual comprehends and orders his world and the illusions upon which that order relies. For Macbeth, Brutus, and Hamlet, this spectrality haunts their very beings, their ability to know how to read the world around them, their place within it, and their futures. The extremity of their reactions is starkly justified, for in each instance, the intractable ghost exposes to the gazing subject the seeds of his own destruction.
University of Edinburgh
 For more on the range of contemporary beliefs and theological perspectives as to the nature of such sightings, see Peter Marshall’s Beliefs and the Dead, esp. 129-41 and 246-47.[back to text]
 Lavater’s text was originally published in Zürich in 1568 and then in English translation in 1572, becoming one of the most influential works on ghostlore in the early modern period.[back to text]
 A similar account occurs in André Du Laurens’ A Discourse of the Preservation of the Sight (translated into English in 1599), which claims that melancholics may be influenced by the ‘medling of evill angells, which cause them oftentimes to foretell and forge very strange things in their imaginations’ (1599: 100). Robert Burton’s The Anatomy of Melancholy also supports the connection between melancholy and the devil (1621: Sig. E3[r]).[back to text]
 Marshall provides a useful discussion on the absence of a clear division between natural, supernatural, and illusory causes of ghost-sightings. See Beliefs and the Dead, 250-52. [back to text]
 Le Loyer’s French text was first published in Angers in 1586 and later published in English in 1605. [back to text]
 Le Loyer’s definition of the spectre here is ‘a substance without a body, presenting it self sensibly unto men’ — in other words, a spiritual entity that lacks corporeality (B4[r-v]). The term therefore encompasses, but is not limited to, the returned dead.[back to text]
 A.C. Bradley supports this point in Shakespearean Tragedy, observing that early modern ghostlore suggests that a ghost is ‘able for any sufficient reason to confine its manifestation to a single person in a company’ (1991: 136). Reginald Scot refers to this supposed quality of ghosts in The Discoverie of Witchcraft, in which he mocks the fact that ghosts ‘never appeare to the whole multitude, seldome to a few, and most commonlie to one alone’ (1584: 535).[back to text]
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