CIA Director William J. Casey's threats against the news media tell us less about conservatives' paranoia regarding the press than about their abiding schizophrenia regarding government.

Conservatives are of two minds about the federal establishment, regarding it alternately as Beauty and the Beast.

On the one hand, it is this greedy, slavering monster which settles on the backs of honest, decent people, robbing them of income, hobbling them with crazy rules, and sapping them of dignity, initiative and the good life.

On the other hand -- Casey expresses this side of it -- conservatives regard government as a tender flower, fragile, vulnerable, as threatened as a maiden in a fairy tale, who must be protected against villains who steal its secrets, publicize its follies and weaken intolerably its capacity to exist and survive.

The Reagan administration, despite its professed devotion to individual liberties, is, in the interests of protecting Beauty's honor, eager to polygraph great masses of civil servants who are suspect anyway because they work for the Beast and drink coffee and read newspapers on time owed to honest taxpayers. Any time some item is divulged prematurely, all are to roll up their sleeves. Secretary of State George P. Shultz balked at the order and became, in today's jumbled value system, a hero of civil liberties.

The administration has cut back on the Freedom of Information Act. It sought to remove pens from the hands of officials with access to classified information so that they can never write best-sellers that make use of government secrets.

Two government employes have been fired for dishing out the dirt. A former naval intelligence analyst has been prosecuted and convicted for giving spy satellite photographs to a magazine.

Casey is out with his tin sword and shield, striking out in all directions against those who would divulge Beauty's secrets. Several weeks ago, he warned Washington Post editors that they would be hauled into court if they published certain information he deemed harmful to the "national security." He said he wasn't sure what statute applied.

Now James Polk of NBC News has caught Casey's eye for reporting that accused spy Ronald W. Pelton told the Soviets about "Ivy Bells," an operation by which U.S. submarines eavesdropped on Soviet shore conversations.

This information about "Ivy Bells," formerly known as "Holystone" -- who says there are no poets in government? -- has been moving around in the public domain for many years.

In the old days, "leaks" were called tips by the people in government who told friends in the news media about matters not made public. The reporters who received this clandestine information called their stories "exclusives." Often they related to federal schemes which belonged under rocks. Exposed to fresh air, they evaporated, which is what the tipster had in mind.

Now, forbidden stories are known as "leaks" by those who give and those who receive them. By any name, they are deplored by governments of any stripe, although the aversion reached historic proportions during the administration of Richard M. Nixon.

The rage culminated in the Huston Plan, a blueprint for a home-grown KGB that was too much even for the late J. Edgar Hoover, and the formation of the infamous White House plumbers unit, which was masterminded by Charles Colson and undertook activities that led to jail terms for him and his confederates.

But since history is not a favorite subject of this administration, the idea of a plumbers unit has been resurrected at the White House. An arm of a Cabinet-level antileak task force has proposed a special "strike force" of FBI agents to pounce on leakers immediately when the drops start falling. Shades of the break-in of Daniel Ellsberg's psychiatrist's office!

The mad plan was promptly leaked to David Hoffman of The Washington Post and, in consequence, may molder on the drawing-board.

It is inevitable, though, that it will be replaced by some comparably crackbrained scheme reflecting the conservatives' view that what Beast government does, unless it looks good on the evening news, is none of the citizens' business -- but that when it leaks out, Beauty government must be avenged by fair means or foul.

Oh, where is the World Court now that we need it? Its verdict on mining Nicaraguan harbors, a Casey special, would give the country material to make a judgment about the judgment of the CIA director who wants to keep the news media in the dark about what else he has been up to.