In this movie we find Michael stops his car when he sees three horses standing a bit far away from the road. That's precisely how he gets saved when the car bomb explodes. He got out of the car to take a closer look at them as they coincided with the sketch of three horses in the "book with the red cover", Realm and Conquest.
Committed to a fully developed back story, director Tony Gilroy spent a good deal of time establishing the details of "Realm and Conquest" with production designer Kevin Thompson. The director explains that right from the beginning, when he first read the script, he could tell that "Realm and Conquest" was going to be a key prop. In the movie it's a metaphor for truth and justice. In creating the details of the fictional novel, Thompson generated original visuals inspired by German Expressionistic images cut from wood blocks, and Gilroy wrote the first two pages for three chapters of the book. They even went as far as designing a "Realm and Conquest" card game for a scene between Henry and Michael. Thompson offers, "This detail was important to Tony because, in his own life, novels and games similar to 'Realm and Conquest' allow him to connect with his son in a meaningful way."
My question here is: Apart from the connection of the three horses from the sketch of this book, was there any philosophical implications to it? Or was it any reference to any other works of Tony Gilroy?
I was not able to find any account of philosophical or any other implications apart from that connection with the sketch.