Hayward is clear that he intends Knife not to be comprehensive but selective, reflecting his own personal views. It's not surprising, therefore, that he never mentions the Inuit ulu, a wonderful chopping and cutting tool, nor the existence of ceramic knives, despite his avowed love of technology. But he seems not to know how handy a small knife with a serrated edge is: not only does it slice tomatoes easily, it saws through corrugated cardboard and plastic clamshell packaging.
His own views owe less to personal experience than to the desire to write vividly. The result is pretentiously vacuous. Take the sentence from the last paragraph of his introduction: "A knife has a beautiful purity of purpose, it's almost the perfect expression of form that precisely follows function, and yet it is at once a seething mess of elusive, impalpable qualities." Some knives have a purity of purpose, agreed, but knives are too varied (as the book itself illustrates) to be lumped together and then abstracted as "a knife." Form in a knife can indeed follow function, so what is the quality that calls for "almost" and hinders or prevents that "perfect expression of form"? And if to some degree these claims are valid, how can "a knife" at once be "a seething mess of elusive, impalpable qualities"? A seething mess? In a knife? Give us a break!
In like fashion, a horizontal cut is described by Hayward as "the utterly lethal and desperate 'last slice' cut, in which a piece of (usually) bread or meat is squashed flat to the board with the palm of the hand, the fingers stretched back and up in fervent but usually futile hope, and the blade sawn between hand and board" (p. 15). Ever since I first read Marcella Hazan nearly forty years ago, I have been using that cut to slice a chicken breast horizontally in half so it cooks faster and stays tender. I've never, ever cut myself. So what are we to make of "Utterly lethal"? "Desperate"? "Fervent but usually futile hope"? This is a seething mess of rhetoric.
Let me just touch on other problems with Hayward's statements:
Steel is not "a metaphor for permanence, solidity and purity" (p. 18).
Slicing a lemon with a carbon blade will not turn the lemon black, as he asserts (p. 45). The citric acid of the lemon will discolor the blade, however, unless you clean it promptly.
Making a knife blade from steel involves two heat treatments, not one: he ignores tempering the steel.
A newly purchased Chinese cleaver does not arrive "with a lifetime of patina and dripping with butch chic" (p. 78)--at least none of mine ever has.
His first rule of carving, "Rest the Meat," contains an amusing mistake: let the meat rest until its core temperature has dropped to 50 degrees Centigrade or 32 degrees Fahrenheit (my italics, p. 174).
It's safer not to follow Hayward's direction to test sharpness with the tips of your fingers (p. 197). Instead, place the cutting edge gently on your thumbnail: if it's sharp, the blade will catch and not slide.
Leaving aside the empty rhetoric, Hayward's major shortcoming is ignorance about sharpening knives: not only does he misunderstand wire edges, he doesn't realize what steeling and honing a blade accomplish. As a consequence, he abrades his knives to get them sharp. That is a waste of good steel.
Sharpening poses a problem for many people, but the solution is not to be found in Hayward. Rather than spend the money for Hayward's Knife, buy a book or video on how to sharpen knives. One book I can recommend is Ron Hock's The Perfect Edge (it's also available in video). You'll learn about steel from a master blade smith as well as learn how to sharpen a knife properly.