If one could complain about [Five Finger Exercise] (or express doubt at all) it would be on two counts. The first is perhaps largely temporary: the language of the younger characters is full of period slang which has got far enough back to sound dated without as yet taking on a period charm, and, worse, it is the superficial expression of a relationship which has too much heavy whimsy for comfort…. The other cause for complaint may also be rather subjective: it is that, in a period of unmistakably individual, personal drama, Shaffer seems to be resolutely impersonal. (p. 9)

[There] is one noticeable oddity the play has, from which, if we observed it, we might wonder whether Shaffer was more than he first appeared to be. That is the way that the play, while functioning (very well) within a tradition which sedulously avoided eloquence, which cultivated the understated, the matter-of-fact (or to put it in more acceptable terms, tended to depend rather heavily on Harold Pinter's second silence, when what is really happening between people is apparently unrelated, or very slightly related, to what they are actually saying), does suddenly burst out every so often into sizzling monologues in which the characters reveal themselves in quite a different way. (pp. 9-10)

All of these big speeches have one thing in common: they tell us something about the great preoccupation of drama during the decade of theatre of the Absurd and all that: communication, its possibilities and impossibilities…. Rarely do two characters succeed in communicating …, but if this is so, it is not so much because, as it was fashionable to say at the time, communication is impossible, but … because people who can and do communicate perfectly will often fear to communicate. (pp. 10-11)

But still, the playwright does not seem to be personally involved in his play to any significant degree…. This balance of sympathy in a dramatist is of course admirable, and makes for effective drama. But might one not be forgiven for wondering if a vital spark of passion was not missing? (p. 11)

[The Royal Hunt of the Sun] is at once a spectacular drama and a think-piece written in rather elaborate literary terms. As Shaffer himself summarized its theme …, it is 'a play about two men: one of them is an atheist, and the other is a god'.

[Shaffer also stated]:

And the theme which lies behind their relationship is the search for God—the search for a definition of the idea of God. In fact, the play is an attempt to define the concept of God.

                                             (p. 17)

Clearly Shaffer has progressed a long way in his dramatic thinking from the easy naturalism of Five Finger Exercise. The Royal Hunt of the Sun is a chronicle play covering a period of over four years and many thousands of miles journeying. It is, for all that, quite tightly organized, but evidently all the material could not be encompassed in a naturalistic drama—it can be done only by calling on all the resources of the theatre, deriving techniques partly from Kabuki, partly from Shakespeare's way with history, partly from Brechtian epic theatre. (p. 18)

The Royal Hunt of the Sun was a tour de force, to be followed … with another, in its own way perhaps even more extraordinary, Black Comedy. This is a piece of physical theatre at its most exhilaratingly virtuoso, based on an idea of dazzling simplicity. From seeing a Chinese theatre company in action, Shaffer had retained the image of actors creating the idea of darkness by miming it. And from this grew the idea of making a farce by simply reversing the normal light values. (p. 21)

As a piece of sheer theatrical machinery the play is impeccable, as brilliant as anything Shaffer has ever done. And almost indestructible: even in a far less than perfect production the structure carries the play. (p. 22)

The idea [in The Battle of Shrivings] is again, as in The Royal Hunt of the Sun, a head-on confrontation between two different ways of life, two opposing approaches to the business of living. But on this occasion the matter is talked out rather than acted out, and consequently the play seems to be lacking a dimension…. The Battle of Shrivings is a talk- and think-piece very much as many of Shaw's later plays are; it forces us to consider the ideas as ideas, and as such they tend to seem shallow and superficial. (p. 24)

[Though verbally Equus] is in places highly developed and breaks out into real eloquence, it is a piece which only fully exists in the theatre, in terms of the astonishing visual imaging of the action and the way the thought is precipitated into meaningful, unparaphrasable happening….

The action of the play was inspired, Shaffer tells us in his note to the published text, by a real-life case of which he was once told the bare outlines—that a highly disturbed young man had inexplicably blinded a number of horses—and no more. This occurrence has been woven into a texture obviously suggested by (or at least heavily influenced by) R. D. Laing's idea that (to oversimplify drastically) conventional modern psychiatry has been unconsciously moulded by the Establishment into a tool for social manipulation, for preserving the 'norm'. (p. 27)

[What Shaffer] shows us, not really tells us—is the process of Alan Strang's gradual deviation from the respectable norm, into neurosis and a crime of cruelty to animals which is found universally shocking, inexplicable and prima facie evidence for his insanity and desperate need for psychiatric treatment which may be hoped to restore him to 'normality'. Linked with this in the play's loose-seeming yet taut and economical structure is a progressive demonstration of the hollowness and self-questioning of Dysart, the psychiatrist who is charged with this job of mental restoration. Shaffer does not make the elementary mistake, any more than R. D. Laing does, of romanticizing madness into a vision of the truth denied to the 'sane', but he does show us Alan's particular brand of insanity as a legitimate and valuable response to experience which brings its own benefits and has to be emasculated by society in the cause of self-preservation: Dysart, with his arid, uncommunicative relations with his wife, his academic devotion to his pet dream-world of classical Greek antiquity, comes eventually to a recognition that at the very least 'That boy has known a passion more ferocious than I have felt in any second of my life'. (pp. 28-9)

The questions [raised by the play] continue to vibrate after the play is over. But the fact that they do so is not so much because of Shaffer's verbal formulations, eloquent though they be. It is because in the play we ourselves have lived through Alan's experience with him, we have experienced vicariously some of his ecstasy in naked, pulsing contact with his god, we have made our own oblation to the dark gods of his dreams. The theatrical experience the play offers is mind-enlarging because it gets at our minds through our emotions, our instincts. It does not expound Laing's theories, it inexorably shows them worked out in practice, and silences argument. Its theatrical logic and power are unarguable, and if something of our instinctive response seeps into our intellect subliminally, that is probably no bad thing. (p. 31)

It is an extraordinary development, from the sober, old-fashioned, intelligent but scarcely profound formulations of Five Finger Exercise to the equally controlled yet in effect explosive expression of Equus…. [Shaffer's] gradual, unsparing exploration of the expressive possibilities of his chosen form, in which technical experiment has been accompanied by (necessitated by, no doubt, since as Shaffer says, the content dictates the form) an uncompromising rethinking of the material proper for drama, his own as well as anyone else's, has little by little established him as a major figure in world drama, a theatrical thinker who triumphantly escapes all narrow definitions and ends up a unique phenomenon, like nobody but himself. After Five Finger Exercise we might have agreed that the play was 'promising', and felt pretty certain that we knew exactly what it promised. After Equus there is just no guessing what he may do next, but it seems inevitable that it will be grand and glorious. (p. 32)