Do you know him?

There’s an invisible
But a real individual;
Who has two faces;
One is dark;
The other, bright
And shining;
Each face has,
Its own power;
One, the power
To attract
The good things
Of life;
The other, the power
To repel
The good things
Of life.
Can you say who this
Individual is?
That individual
Is called Attitude.