Composition
The album's opening track "War Pigs" was originally intended to be called "Walpurgis". It was then changed to "War Pigs", which the band intended to name the album until it was changed to Paranoid after the record company became convinced that the song of the same name had potential as a single. Butler explained his intentions to Classic Albums: "I wanted to write a song called 'Walpurgis' – you know, the Satanic version of Christmas – write it about that Satan isn't a spiritual thing, it's warmongers. That's who the real Satanists are, all these people who are running the banks and the world and trying to get the working class to fight the wars for them. We sent it off to the record company, and they said, 'No, we're not going to call it that. Too Satanic!' So I changed it to 'War Pigs'." In his autobiography I Am Ozzy, vocalist Ozzy Osbourne recalls, "It was originally going to be called 'Walpurgis' ... which was a term for a black magic wedding or something. Then we changed it to 'War Pigs', and Geezer came up with these heavy duty lyrics about death and destruction. No wonder we never got any chicks at our gigs. Geezer just wasn't interested in your average 'I love you' pop song ... Geezer also liked to put a lot of topical stuff, like Vietnam references, into our songs. He had his ear to the ground, Geezer did."
The song "Iron Man" was originally titled "Iron Bloke". Upon hearing Iommi play the main guitar riff for the first time, Osbourne remarked in awe that it sounded "like a big iron bloke walking around". The title was later changed to "Iron Man" as bassist and lyricist Geezer Butler composed the lyrics. The riff to "Iron Man" is iconic among heavy metal guitarists, with Osbourne declaring in his memoir that "...Tony Iommi turned out to be one of the greatest heavy rock riff-makers of all time. Whenever we went into the studio we'd challenge him to beat his last riff – and he'd come up with something like 'Iron Man' and blow everyone away." Butler wrote the lyrics as the story of a man who time-travels into the future and sees the apocalypse. In the process of returning to the present, he is turned into steel by a magnetic field. His attempts to warn the populace are ignored and mocked. This causes Iron Man to become angry and vengeful, causing the destruction seen in his vision.
"Electric Funeral" also contains apocalyptic imagery dealing with nuclear warfare. In The Last Supper concert film, Iommi remembers that at the time with most bands "it was all the 'flowers in your hair' and we wanted to sing and play about the other side of life." In the 1992 documentary Don't Blame Me Osbourne said: "It was me and five kids living in a two bedroom house. My father worked nights, my mother worked days, we had no money, we never had a car, we very rarely went on holiday ... And suddenly, you know, we hear about 'If you're going to San Francisco be sure to wear a flower in your hair'. And we're thinking, (contemptuously) 'What the fuck is San Francisco? Where is this? What's all this flower shit? I've got no shoes on my feet.'" "You could just see that a lot of things were going wrong in the world," Butler recalled to Classic Albums in 2010, "and no one was saying anything about it. Bob Dylan had long since faded from the present memory and there was nobody talkin' about the things that I wanted to talk about – political stuff – so that's what inspired me."
In 2013, Butler told Mojo magazine that the song "Paranoid" was "about depression, because I didn't really know the difference between depression and paranoia. It's a drug thing; when you're smoking a joint you get totally paranoid about people, you can't relate to people. There's that crossover between the paranoia you get when you're smoking dope and the depression afterwards." In 2015, Butler elaborated further to Dave Everly of Classic Rock: "I used to be a cutter. I'd cut my arms, stick pins through my fingers, that kind of thing. I used to get really depressed and it was the only thing that could bring me out of it. If Sabbath hadn't made it, I'd have been long dead. I'd have killed myself." According to Mick Wall's book Black Sabbath: Symptom of the Universe, Butler was dead set against the song because he thought it too closely resembled Led Zeppelin's "Communication Breakdown", with the bassist admitting, "I thought it was so much like that we couldn't possibly get away with it ... They were our favourite band by that time".
"Planet Caravan" was an unusually quiet song which showcased that the band was capable of more than bone-crushing guitar riffs. Iommi admitted that the band had doubts about the mellow number, telling Classic Albums, "It was almost one of those 'Should we do this?'" with Butler adding, "We just came up with that in the studio and it was really laid back so and we didn't want to come out with the usual love crap. So it was about floating through the universe with your loved one, instead of 'Let's go down to the pub and have some chips', or whatever ... Just taking a spaceship out into the stars and having the ultimate romantic weekend." Django Reinhardt's jazz influence is apparent on Iommi's guitar playing.
"Hand of Doom" dealt with the problem of soldiers returning from the Vietnam War strung out on heroin, which the band witnessed first-hand when they played two American Army bases but, as Butler observed to Matthew Longfellow in 2010, there was "nothing on the news about this. There was no programs telling you that the US troops in Vietnam, to get through that horrible war, were like fixing up and all this kinda thing. It just stuck in my head and when we got to "Hand of Doom", that's what I wrote it about".
According to Butler, Ward's drum solo "Rat Salad" resulted from the band having to play eight 45-minute spots a night in Europe early in their career. "Bill used to fill out a whole 45 minutes doing a drum solo just to get rid of that 45 minutes," he revealed to Classic Albums. "I have no idea where the title came from, though." While Butler may have now forgotten where the title of "Rat Salad" came from, in 1971 he was on record stating it came from a joke about Ward's hair having not been combed.
In 2013, Sabbath biographer Mick Wall described the closing track on the album, "Fairies Wear Boots", as a "hard-driving riff sweetened by a beautifully baleful melody" with a lyric written by Osbourne about a nasty encounter with a group of skinheads.
