BOSTON - It was Aristotle who said, "The whole is greater than the sum of its parts."

The Boston Celtics are proving that to be true.

As we head down the final quarter of the NBA season, perhaps the biggest thing that separates a winning team like the Celtics from a losing team is a sense of unity.

The Celtics look like a team. They work together for one common goal: to win. That means sitting when you'd like to play, or passing when you'd like to shoot. The idea of being forced to share the ball - or court - at any point in a game doesn't exist for the Boston Celtics. It's something they embrace.

And it goes beyond just cycling the ball around or passing up one shot for a better shot. It's on the 50-50 balls that players like Jared Sullinger dive on up 20 points against the Blazers. It's on the defensive end on plays that have Evan Turner diving out of bounds to save a loose ball late in Friday's fourth quarter. And yes, it's even on the bench when someone like Amir Johnson doesn't play a single minute in the fourth quarter and is still up cheering on his teammates during their comeback.

There is no superstar. We've exhausted that storyline. But that seems to be working for a Celtics team with a group of players who understand their roles and contribute in ways they can while still staying in their lanes.

And that's becoming something opposing teams are noticing as the Celtics climb up the Eastern Conference standings, having won 16 of their last 20 games.

"I just think that they've figured out who they are," Knicks coach Kurt Rambis said before Friday's game. "That's what the really good teams in the league besides having talent, everybody understands their roles, they understand how to execute at both ends of the court, and they understand how to play unselfishly and off each other and for each other.

"When it clicks in with any team how to play unselfishly, then that team is going to grow and they're going to prosper as a result of that. How far they go usually depends on how talented they are. If there's enough talent to play at the upper echelon levels or not. But I think they've done a good job of recognizing their defensive capabilities, their ability to pressure people, and their willingness to execute their offense with a lot of movement. They create a lot of havoc on ball, off ball, and they keep the defense always having to make these multiple reactions."

Before the regular season even began, the Celtics were thought to be the deepest team in the NBA. That isn't to say they were top heavy, but they could come at you with their starters and keep coming almost just as hard when they dipped into a bench that now features Turner, Marcus Smart, Kelly Olynyk, and others.

Some wondered how the No. 8 guy on the depth chart would feel about coming off the bench knowing he could probably make a case to start. But that hasn't been an issue. And that's good, because the Celtics understand they aren't a good enough team as a group of individuals.

"I think the biggest thing is the guys that aren't playing have to stay ready through these types of runs and be ready to impact us in a winning way when they get their opportunities like Jordan Mickey did the other night," Brad Stevens said. "But there comes a time in each season if you're lucky as a coach that that stuff is really, really well defined in the eyes of the players. Because it can be as well defined in the coach's eyes as you want but it has to be well defined in the eyes of the players and then you're coaching basketball, you're playing basketball, you're enjoying it, there's a fun part of it as a team and everything else."

Stevens says that unselfishness ultimately falls on the players. He's right. If Paul Pierce, Kevin Garnett, and Ray Allen continued to play the way they played before joining forces, the Celtics would still be looking for that 17th banner.

"They have to make that choice," Stevens said. "That has to be a conscious choice and it's a hard choice to make."

A hard choice that becomes a lot easier when wins follow.

"I think we just learned we gotta play that way," Isaiah Thomas said. "For us to be a good team we have to share the ball, we gotta try to make the right plays, each and every time down because the percentages say, when we go 1-on-1, we’re not that good of a team. And we know that."

Quick: Who's the MVP of Friday's win over the Knicks? It's not an easy answer, is it? Yes, Thomas had a game-high 32 points, but Turner was probably the most important player in the fourth quarter. Tyler Zeller stepped up. Avery Bradley had the game-winning layup. Jae Crowder and Smart played lockdown defense on Carmelo Anthony on that final Knicks possession.

The real answer? It doesn't matter.

"We really don't care about who gets the credit for the most part," Turner said. "We all have fun and we all have guys that are all ready to go and play. Each night, it can be someone else saving the game and that's a huge thing, especially when you can lose yourself inside something bigger."    

The Celtics haven't lost themselves. If anything, they've found themselves.