Billionaire investor and philanthropist Warren Buffett has been dazzling us with wisdom for nearly half a century

As one of the most successful value investors in the world, the Oracle of Omaha understands what it takes to run a successful business -- including its hiring practices.

For anyone assuming hiring duties or building a company or team, take this Buffett quote to heart:

We look for three things when we hire people. We look for intelligence, we look for initiative or energy, and we look for integrity. And if they don't have the latter, the first two will kill you, because if you're going to get someone without integrity, you want them lazy and dumb.

That now-infamous quote was taken from a talk Buffett gave to MBA students at the University of Georgia years back. 

Buffett's 3 things to look for when hiring people 

In a knowledge economy, obviously you need smart people with the mental capacity to do the job exceptionally well. Case in point, Apple co-founder Steve Jobs famously quipped, "It doesn't make sense to hire smart people and tell them what to do; we hire smart people so they can tell us what to do."

But intelligence alone doesn't cut it, whether in investment or human performance. As Buffett asserts in his speech, "You don't need to be a rocket scientist. Investing is not a game where the guy with the 160 IQ beats the guy with 130 IQ."

In the hiring requirement of "energy," Buffett clarifies it as someone who takes initiative; it's having that entrepreneurial spirit and the desire to make things happen, whether for you or your company.

But integrity? It's the glue that holds everything together. It's the most important quality that you should develop for success; and it's the most important quality--non-negotiable--you should look for when hiring others.

Why integrity is so important

Let me ask you: Would you hire someone who is brilliant and technically savvy, who is driven and takes initiative, but who cuts corners, isn't reliable, misses meetings and deadlines, and isn't fully honest or accountable?

I didn't think so. And while Buffett semi-jokes in the video, you really are asking for a lazy and dumb person when hiring someone without integrity. Buffett depicts people with integrity as generous, honest, and willing to do more than their fair share. 

Here are five compelling reasons why you should never doubt putting integrity above intelligence and energy (or any other hard skill or competency) when hiring people.

1. You never question their character.

Integrity implies the quality of possessing and faithfully abiding by high moral principles. This is good for business and the workplace. When hiring a whole bunch of people with integrity, it lays out an immovable foundation of trust and confidence to define your culture.

2. You can rely on them doing the right thing.

The word itself comes from the Latin adjective integer, meaning whole or complete. People of integrity follow their moral compass in all circumstances because it's the right thing to do. And that's what leads to success.

3. You can count on them to keep their promises.

People with integrity give and keep promises, even reluctantly at times, but once they give their word on something, you can count on them following through. 

4. You can expect them to be radically honest.

People with integrity aren't afraid of the truth, and they view the world as it really is, not as they wish it to be. They demand truthfulness and honesty in themselves and in others. They are even willing to tell the truth if it is not in their favor; it's better for them to be unquestionably real than to mislead or deceive others (and themselves, in the process).

5. You can be assured that their words match their actions. 

It's much easier to trust a person of integrity because their thoughts are consistent with their words, and their words are backed up by their actions, which is golden in collaborative work environments. If you hire someone who consistently says one thing, but his or her actions say something else, it may be time to overhaul your hiring process, including revising the interview questions you should be asking to assess a person's integrity