Colin Farrell says his eldest son is "extraordinary".
The 37-year-old actor has two sons, James, 10, whose mother is model Kim Bordenave, and three-year-old Henry with Polish actress Alicja Bachleda-Curus, and they have been spending more time together recently.
Colin is delighted with James' progress as he has Angelman Syndrome, a rare neuro-genetic disorder that impairs his speech, movement and balance, but despite his condition he is making amazing progress and is an inspiring child.
Colin told UK TV show 'This Morning': "James is 10 and Henry is four and James has a thing called Angelman Syndrome which is a neurogenetic condition that affects motor skills and speech.
"He took his first steps when he was four years of age and he has no verbal speech, he has a greater ability with receptive language, like he'll understand things and directions but he's an extraordinary, extraordinary boy."
Although James is the elder brother, Colin thinks Henry will eventually take on responsibility for his sibling as he begins to understand his brother's disorder and realise he can help him.
The 'Saving Mr. Banks' star said: "It's weird because in his own time Henry will realise that he is something of a bigger brother, he doesn't get it quite yet ... they're two really good boys so they'll figure each other out."
The Irish actor has also claimed that during his days of abusing drugs and alcohol he was scared that people would see him as being weak but now he is at ease with his feelings.
He said: "Back then, anyone that was OK to be silent in company would kind of agitate me and I'd be afraid that they'd see a certain weakness in me, but I was loud enough to continually hide stuff."