In the old days, “vigilance” referred to one neighbor looking out for another. In today’s world of foreign and domestic terrorists with the easy ability and desire to concoct devices that can kill and maim great crowds of innocent people in the blink of an eye, that vigilance is reflected in the law enforcement slogan, “If you see something, say something.”

Even with all of today’s advanced technology and modern law enforcement techniques, making communities safe — whether from random bombers, rampaging gunmen or even from devoted foreign terrorists — still comes down to neighbors looking out for one another.

Folks in Chuckatuck understand this point better, perhaps, than anybody else in Suffolk. The village is a close-knit community where people usually know their neighbors more than just to pass pleasantries across their driveways a few times a week. For many of the residents of Chuckatuck, the village has been home to their families for generations, so grandmothers grew up together, fathers were best friends and members of today’s generation of young adults grew up playing Little League baseball against each other.

Those kinds of ties help create a community of people who will look after their own. Folks in Chuckatuck hardly need to be told to watch out for people prowling around in neighbors’ back yards — that already comes naturally, and it might have paid off last week with the arrest of a man alleged to have set a string of fires to sheds and outbuildings in a part of the village near his own home.

For four months, officials from the fire marshal’s office have been investigating a series of suspicious fires, quietly asking for help from the community in solving the case. When they announced the suspect’s arrest on Thursday, a bit less than a week after residents from the community went on the record to news editor Tracy Agnew about the fears the rash of fires had caused, authorities said that public assistance had been vital to their efforts.

It remains to be seen whether that public assistance came in the form of a description or even identification of the suspect by an eyewitness or some other type of information that might have helped investigators make the connections that led to the arrest. But it’s clear nonetheless that the Chuckatuck community’s sense of responsibility for helping to deter a dangerous crime wave played a part in the subsequent arrest.

Call it vigilance. Call it neighbors helping neighbors. Call it common sense. Whatever you call it, though, the world could use more of it.