Quis custodiet ipsos custodes? Who is to guard the guardians themselves? Juvenal’s phrase has been going through my head for the past few days as I’ve observed the steady drumbeat of leaks coming from Robert Mueller’s special counsel investigation of the President.

On Wednesday the Washington Post reported that five unnamed officials had said that the President is now under investigation for obstruction of justice for his firing of FBI Director James Comey. A day later, similarly unnamed sources said that the President’s adviser and son-in-law Jared Kushner is also under investigation. Let’s be clear: These leaks are immoral and probably illegal. They are serious violations of professional codes of ethics. They seem to have no purpose other than inflicting political damage on the administration. And they are coming from multiple sources connected to the Special Counsel’s investigation.

But this is only the beginning. James Comey’s testimony described Mueller as a close friend. Now that his investigation has expanded to include Comey’s termination — and even Comey himself admitted the President had the authority to fire him—that puts Mueller in the position of investigating the firing of a close friend, with that friend’s testimony being crucial to the case. This is plainly a conflict of interest.

Add to that the list of Mueller’s hires to aid him in the investigation. Michael Dreeben is a leftist. Jeannie Rhee was a lawyer for the Clinton Foundation who donated thousands to “Hillary for America.” James Quarles donated to the same group. And Andrew Weismann, like James Comey, has a reputation for disrespecting the rights of those under investigation. Mueller has hired people with a partisan interest in the outcome of this investigation. The whole idea behind appointing a Special Counsel is to remove the investigation from partisan political influence. That objective is not being met here.

Notice that I have not yet mentioned possible collusion with Russia. That’s the original subject of the investigation, and there is still, after a year, no evidence whatever that it took place. The Special Counsel is investigating whether the President obstructed an investigation into something that never happened — by asking a subordinate to tell the press the truth, that he was not even under investigation for that thing that never happened.

It’s clear where this is going. Mueller might as well announce the conclusion in advance. No matter what Trump and his associates have done or have failed to do, Mueller intends to bring charges. He is conducting a wide-ranging fishing expedition to produce evidence of a crime to be named later. “Show me the man, and I’ll show you the crime.”

The President, plainly, is in a no-win situation. Firing Mueller, though entirely justifiable, would ignite a political firestorm. Allowing him to proceed guarantees an eventual charge of obstruction of justice and whatever else the probe can unearth in its limitless exploration of the affairs of the President and his advisers. In the meantime, leak after leak will keep the investigation on the front pages, inflicting maximum damage on the administration and its priorities.

What can President Trump do? Here’s my suggestion: Appoint a Counsel to lead an investigation into the investigation. There is already significant evidence of illegal activity on the part of the investigators. If the Washington Post is to be believed, at least five sources connected to the investigation have acted unethically and probably illegally. James Comey himself, having admitted that he leaked his notes to the New York Times by way of a Columbia University professor, should be investigated as well. In addition to leaks, the Counsel should investigate the possibility of collusion between the investigators and Democratic Party officials.

We know that key investigators have deep ties to left-wing groups and to the Democratic Party. Several were significant donors to the Hillary Clinton campaign. What other links do they have to left-wing groups, to the Democratic Party, and to former and current officials? Are Democrats in Congress, in administrative agencies, or in left-wing groups collaborating with the Special Counsel’s team to damage the Trump administration? Exactly what ties, financial and otherwise, do investigators have to political actors in Washington?

There are several advantages to the appointment of a counsel to investigate the investigators. First, it will help to keep that investigation within proper ethical bounds. It will discourage leaks and help to protect the rights of those under investigation. Second, it will provide some partisan balance, keeping the Special Counsel’s investigation from becoming (more of) a partisan witch-hunt. The counsel would need to be someone who would rightly be suspicious of partisan influence in the Special Counsel investigation, would be willing to issue subpoenas in search of information about leaks and other matters, and would not grant immunity willy-nilly as Comey seems to have done in the investigation of Hillary Clinton. Third, the appointment of a counsel to investigate the investigation would demonstrate to those within the deep state working against the President and his administration that there will be consequences for wrong-doing. As it stands, those doing the leaking appear to be convinced that they are invulnerable, that the ordinary ethical and legal rules do not apply to them and that they can therefore break them with impunity. They need to be put on notice that they have to follow the law.

As Glaucon says to Socrates in Plato’s Republic, “that a guardian should require another guardian to take care of him is ridiculous indeed.” But that, sadly, is where we are. We need a guardian to watch over the guardians, and soon.

Daniel Bonevac is Professor of Philosophy at the University of Texas at Austin.