Songfacts®:

• Dream Theater close their eponymous twelfth album with this epic five part suite, which comprises:
  I. Paradoxe de la Lumière Noire
  II. Live, Die, Kill
  III. The Embracing Circle
  IV. The Pursuit of Truth.
  V. Surrender, Trust & Passion
• Guitarist John Petrucci told Ultimate-Guitar.com how he wrote such a multi-part song with multiple movements. "The first thing you start with is that you know you're gonna do that kind of piece," he said. "You go in knowing, 'OK, this is gonna be an epic piece. It's gonna be 20 minutes long.' You know you have room for parts to develop and grow. Once you do that you can get a good idea of the type of shape of it that you want."
  
  He added: "For example in this case, I knew I wanted us to do an atmospheric breakdown in the center with almost like a ballet-sounding string thing just to be totally, totally different in the middle. If you kinda know that thing you have a little bit of a blueprint."
• Petrucci told Ultimate Guitar that he already had the main theme for "Illumination Theory" before he started working on it in earnest. "It was, 'OK, this is going to be the theme. This is happening at the start,'" he said. "Similarly with the ending progression that's repeating, that's something we had worked on at a soundcheck in Asia at one point. As soon as we did that, I'm like, 'This will be used for the ending of a song somewhere on our next album.' So you have an idea and you have these little pins like on a map. It's a matter of shaping what happens in-between those moments."
• The song's vibey outro was something that keyboardist Jordan Rudess created at home. He told MusicRadar: "I was playing it, these three chords, and I loved it. I didn't know what the guys would think, but I played it for them, and John Petrucci was like, 'That's really cool.' So we decided that it would be a neat surprise at the end. It's piano, guitar and Seaboard. It relaxes things after this enormous trip you've been on. So if you're still listening, if you hang in there, that's how we tag it out."
• Rudess told Loud Online about this song's classical music influence. "Well," he said, "I come from a Julliard classical music background, I like pieces where motifs and ideas get developed and changed and can be allowed to breathe and that track's certainly not any sort of standard pop song format in any way, shape or form. I just love the fact that we're just really going for it and there's all these kind of progressive parts where there's interesting counterpoints and harmonic changes going on, and I'm also very fond of the fact that in the middle section of 'Illumination Theory,' there's that whole section that really is very ambient and very electronic-soundscapey which leads into a string ensemble part which was actually done with the help my young protégé Eren Başbuğ, a young Turkish arranger/conductor who took what I had composed on my keyboard and fleshed it out for a string orchestra. And then the string orchestra came into the studio and he came in and conducted them."
  
  "That piece just has so much to it," he continued. "I love when we get deep and it all gets a bit wild, and I also love that in the midst of all that madness, we really let that middle section to really breathe and slow down and be melodic like a movie score."