As Philadelphians consider a tax increase for our schools, we must remember this truism: In education, money matters. It pays for teachers, and specialists, and principals, and books, and buildings. It provides intensive resources to the children who have the highest needs. It is why our wealthier suburban neighbors regularly raise their taxes, and why schools in states like Massachusetts perform so well.

We have the evidence in Pennsylvania. In the middle of America's great recession, using stimulus funds as a backstop, the commonwealth finally took steps toward more fully funding our public schools. The results were immediate: Among each cohort of students, including in Philadelphia, achievement scores increased.

Full funding, however, never came. Instead, in 2011, Gov. Tom Corbett cut $851 million from education funding, with the poorest schools bearing the largest cuts.

The result was as predictable as it was devastating. Communities across the commonwealth raised taxes, but for many it was not enough. By the time the cutting was over, 27,000 people disappeared from the public education workforce. Achievement scores plummeted.

In Philadelphia, a "doomsday budget" became austere reality. Amid bloodless calls to "live within its means," the School District let go teachers, counselors, assistant principals, central office administrators, and support staff. As a result, class sizes ballooned and 23 schools closed. Teachers became janitors, while principals learned how to administer insulin to students with diabetes. By any measure, the quality of education suffered.

In recent years, with regular tax increases, Philadelphians have provided a needed measure of stability and modest investments for our schools. Professionals have returned and programming has increased.

Even with the added local funding, however, the depth of our underfunding remains unconscionable, with the district likely underfunded by approximately a billion dollars each year. As a result, class sizes remain too large. Teachers pay for supplies out of their own pockets. Billions of dollars' worth of repairs are needed for an aging set of buildings. And the hardest-to-reach children miss the intensive intervention they need to help them fulfill their potential, because we cannot afford it. Stability, in other words, should never be confused with sufficiency.

Meanwhile, another reckoning looms on the horizon, with the district facing budget deficits averaging $200 million per year, placing the small gains our schools have made at risk.

After kissing babies or cutting ribbons, opposing tax increases is the easiest thing for a politician to do. Rather than succumb to this siren call, however, the mayor and City Council are asking Philadelphians to pay a tax increase to keep doomsday at bay. And they are doing so in the year before their possible reelections.

In considering the mayor's proposal, we must overcome two arguments. Each has at least a vein of truth, but neither will solve the crisis we face.

First is that we should demand "efficiencies" before increasing school funding. In a district already cut to the bone, these calls are the equivalent of demanding a hungry child prove her pockets are empty of crumbs before offering her a meal, well knowing that no amount of scraps there will adequately fill her stomach.

Second is that education is the state's responsibility, and low-wealth communities have already done more than their share. I know this argument well, because as a member of the team pursuing a landmark school-funding case against the commonwealth, I make it regularly. But litigation is slow and uncertain. And in our courtrooms, the plaintiffs face the same obstacles that advocates confront in the halls of the Capitol: an intransigent legislature, which passionately argues that education is not a fundamental or important right, and which has no intention of fixing this problem.

In other words, the state cavalry is not coming anytime soon. In the meantime, only Philadelphians can save Philadelphia. The question for all of us is whether we are willing to do so.

There is a fundamental debate at the center of all this. It pits those who are willing to invest in every student as a future fellow citizen against those who do not want to pay for another family's child, using the specter of "government schools" and "urban" kids as bogeymen.

Philadelphians will not be spared from such a debate. For whether the money is routed through Harrisburg or City Hall, the fortunate among us will have to pay if we want quality schools. When it comes to education, there are no easy shortcuts or miraculous new efficiencies.

As citizens, we must hold on to the recent gains we have made with everything we have, by our fingernails if necessary. This tax increase, which will not provide the growth that Philadelphia students deserve, will at least ensure that the recent gains we have made are preserved.

For all our children, returning to doomsday is not an option.

Dan Urevick-Ackelsberg is an attorney at Public Interest Law Center.