In summary Gov. Jerry Brown is famously enigmatic, a difficult-to-predict politician who said decades ago that he likes to “paddle a little bit on the left side, then… a little bit on the right.” But every year he drops clues to his governing approach in a raft of letters he writes to the Legislature detailing why he’s vetoed certain bills. Together, they offer a window into the governor’s mind.

Gov. Jerry Brown is famously enigmatic, a difficult-to-predict politician who said decades ago that he likes to “paddle a little bit on the left side, then… a little bit on the right.”

But every year he drops clues to his governing approach in a raft of letters he writes to the Legislature detailing why he’s vetoed certain bills. Veto messages are required by state law; most of Brown’s are simple notes of five or six sentences, straight and to the point.

Sometimes, though, Brown expounds with an obscure historical reference or an impassioned philosophical argument. He referenced the legal systems of ancient Rome and 17th century England in a three-page-long veto message in 2013, and, in a 2014 veto message, instructed lawmakers to read a 50-year-old essay in the Federal Bar Journal.

Together, the veto messages provide a window into the mind of California’s longest-serving governor. Though Brown doesn’t veto many bills—about 13 percent since he returned to the governor’s office in 2011—his vetoes express a consistent set of themes about how government should function.

He writes many of the messages himself, frequently by dictating to a staff member. And when he edits one written by an aide, he weighs in on everything from “the literary to the substantive to the grammatical,” said his executive secretary, Nancy McFadden.

This year Brown, a Democrat, signed 859 bills and vetoed 118. Here’s what his vetoes reveal:

Every now and then, Brown puts the brakes on big government.

Having signed nearly 17,000 bills into law during his four terms as governor, he is no libertarian. Yet he sometimes sees a limit to how many rules we need.

“If people can’t smoke even on a deserted beach, where can they? There must be some limit to the coercive power of government,” Brown wrote in rejecting two bills that would have banned the practice.

He also vetoed a bill that would have put new restrictions on drivers age 18 to 21, writing that it would “create a burden on a segment of adult Californians that are no longer seen as a minor in the eyes of the law.”

Brown biographer Chuck McFadden (no relation to Nancy McFadden) said the governor has long displayed a “curious, almost Republican strain of keeping government out of people’s business.”

Brown is cautious about “resisting” President Trump.

Democratic legislators spent much of 2017 railing against the new Republican president, and passed several bills aimed at tweaking or thwarting his administration. Brown signed some of them, including a scaled-back version of the “sanctuary” bill to shield some undocumented immigrants, but rebuffed others.

“While I recognize the political attractiveness—even the merits—of getting President Trump’s tax returns, I worry about the political perils of individual states seeking to regulate presidential elections,” he wrote in vetoing a bill that would require presidential candidates to release their taxes in order to be placed on a California ballot.

“I am not prepared to codify additional requirements in reaction to a shifting federal landscape,” Brown penned in vetoing a bill to incorporate Obama-era regulations on college campus sexual harassment into state law.

The governor also jettisoned a bill that would require the state to preserve scientific data the Trump Administration might try to destroy. Brown said he would simply tell his administration to save the data.

Brown doesn’t often change his mind.

If he vetoed a bill before, he will likely veto it again. And he’s quick to remind lawmakers that he gets the last word. Several veto messages this year included phrases like:

“After twice vetoing prior attempts…” (vetoing a bill regarding wages for workers contracted by the University of California.)

“As I stated in 2014 when I vetoed a nearly identical bill…” (vetoing a measure to require a California trade office in Mexico City.)

“I vetoed a similar bill in 2015…” (vetoing a bill to impound cars after a driver’s second case of reckless driving.)

Brown does sign some bills he’s vetoed in the past—but usually only if lawmakers have made some changes to it.

Brown doesn’t like to enact a law that should be a budget item.

That was his argument for vetoing bills to provide grants to rescue marine mammals and sea turtles, to educate Californians about Valley Fever, and to expand programs for disabled adults.

In vetoing a pair of bills that would create new tax breaks, Brown wrote: “These bills are an end run of the budget process.” He went on to say that the negotiation-filled budget process “is the best way to evaluate and prioritize all new spending proposals, including those that create new tax breaks.”

Lobbyist Chris Micheli, an expert in tax law, said this governor has been more of a stickler than past governors in vetoing tax exemptions: “He wants them done as part of the budget and not stand-alone.”

Brown is wary of creating new crimes and punishments.

Two years ago he vetoed a slew of measures that would have created new crimes—saying that California’s criminal code had already grown to “more than 5,000 separate provisions, covering almost every conceivable form of human misbehavior.”

“This multiplication and particularization of criminal behavior creates increasing complexity without commensurate benefit,” Brown wrote in 2015.

This year he put the kibosh on bills that would have added a $1,000 penalty for assaulting a public utility worker and for taking a photo of someone without their consent and distributing it. And that bill creating a new misdemeanor for false or misleading advertisements related to the sale of cats and dogs? Also a no.

A snippet of Brown’s message on why he vetoed AB 1393, which would have required courts to impound vehicles for 30 days after a driver’s second case of reckless driving.