"Those methods, read on a bright, sunny, safe day in April 2009, appear graphic and disturbing." So Dennis Blair, President Obama's director of national intelligence, stated as he sought to minimize the significance of four previously secret Justice Department memos that employed tortured legal reasoning to authorise CIA agents to use cruel and abusive tactics to interrogate suspects inside secret prisons.

"It was a bright cold day in April, and the clocks were striking thirteen." So begins George Orwell's classic novel of the security state, 1984. It seems unlikely that Blair intended the allusion. Maybe every incoming US director of national intelligence is required to read 1984, and the opening line just stuck with him. But the reference could not have been more appropriate. The four Justice Department memos, spanning 124 pages of dense legal analysis and cold clinical descriptions of sustained, systematic abuse of human beings, do precisely what Orwell foretold: twist the English language in order to approve the unthinkable.

How else could one conclude that slamming a suspect's head against the wall, depriving him of sleep for more than a week, forcing him into stress positions and dark, confined boxes for hours at a time, and waterboarding him repeatedly – 183 times in the case of Khalid Sheikh Mohammed, and 83 times in the case of Abu Zubaydah - was not "torture," and not even "cruel, inhuman, or degrading?"

All such conduct is prohibited by the Convention Against Torture and Other Cruel, Inhuman, or Degrading Treatment or Punishment, a treaty the US signed and ratified into law in 1988. So the lawyers' job should have been to tell the CIA that they could not use these tactics – which in any event have never been shown to be more effective than alternative forms of interrogation. Instead, the lawyers – including John Yoo, now a professor at Berkeley and Jay Bybee, now a federal judge - undertook to read the treaty prohibitions to authorise precisely what they were designed to prohibit.

The legal arguments employed are stunningly bad. None of the interrogation tactics result in severe physical or mental pain or suffering, the threshold required for torture, the lawyers reasoned, because US military trainers have used most of them on our own soldiers to train them to withstand abuse by their captors. But to be subjected to waterboarding in a voluntary setting by someone you know is on your side and has no intention to harm you is completely different from being subjected to such treatment by the enemy, where the fear of death is perfectly reasonable. The fact that my children sometimes hide in a dark box when playing hide and seek doesn't meant that it's not inhuman, degrading, and possibly torture to confine a human being against his will to such a box for hours on end. The fact that consensual sex does not inflict severe physical or mental pain or suffering does not mean that rape doesn't.

Most of the attention thus far has gone to the memos interpreting the criminal torture statute, but the most outrageous memo is surely the fourth one [PDF], signed by Stephen Bradbury, which argues that these tactics are not even "cruel, inhuman, or degrading" – a much lower threshold than torture. The memo first contends that the treaty's prohibition on such abuse does not protect foreign nationals held outside our borders, only Americans. But the very purpose of an international human rights treaty is to protect all human beings from outrages to human dignity – and dignity does not turn on what passport you happen to hold.

The memo goes on to argue that even if the prohibition extended to foreign nationals held abroad, none of these tactics are in fact cruel, inhuman, or degrading. If you asked any class of 10-year-olds the same question, I doubt a single one would disagree that forced nudity, stress positions, slamming people into walls, slapping their faces and abdomens, confining them in dark boxes, and suffocating them until they fear they are drowning, are cruel, inhuman, and degrading. Indeed, that is their point.

But the 10-year-olds would not have had the benefit of a legal education. The Justice Department lawyers reasoned that only conduct that "shocks the conscience" can be considered cruel, inhuman or degrading, and that even though the Supreme Court has held that the slightest use of force "shocks the conscience" in a domestic criminal investigation, the very same tactics lose their shocking character when perpetrated in the name of national security.

In fact, federal courts have held that merely questioning an individual while he is suffering from pain not inflicted by the questioners "shocks the conscience." If that's the case, then logic would seem to dictate that deliberately inflicting pain for the purpose of questioning also shocks the conscience. But in this instance, neither logic nor law dictated. The end was deemed to justify the means, and these lawyers were only too willing to torture the law to let the torturers loose. Long live George Orwell.