Joseph Stack, the 53-year-old software engineer who crashed his small plane into an office building in Austin, Texas, on Thursday, detailed his frustration with the federal government — and particularly the Internal Revenue Service — in a manifesto he posted online.

Its final words:

"I saw it written once that the definition of insanity is repeating the same process over and over and expecting the outcome to suddenly be different. I am finally ready to stop this insanity. Well, Mr. Big Brother IRS man, let’s try something different; take my pound of flesh and sleep well."

Law enforcement authorities said they believe the 3,200-word manifesto is authentic.

"If you're reading this, you're no doubt asking yourself, 'Why did this have to happen?'" the posting read. "The simple truth is that it is complicated and has been coming for a long time."

The posting details Stack's "real American nightmare," which he said began in the early 1980s.

"Some friends introduced me to a group of people who were having ‘tax code’ readings and discussions. In particular, zeroed in on a section relating to the wonderful 'exemptions' that make institutions like the vulgar, corrupt Catholic Church so incredibly wealthy. We carefully studied the law (with the help of some of the 'best', high-paid, experienced tax lawyers in the business), and then began to do exactly what the 'big boys' were doing (except that we weren’t steeling from our congregation or lying to the government about our massive profits in the name of God)."

The purpose, Stack wrote, was to "bring about a much-needed re-evaluation of the laws that allow the monsters of organized religion to make such a mockery of people who earn an honest living. However, this is where I learned that there are two 'intrepretations' for every law; one for the very rich, and one for the rest of us ... "

"That little lesson in patriotism cost me $40,000+ 10 years of my life, and set my retirement plans back to 0," the posting continued. "It made me realize for the first time that I live in a country with an ideology that is based on a total and complete lie."

During his late teens, Stack studied engineering in Harrisburg, Pa., where he lived on "peanut butter and bread (or Ritz crackers when I could afford to splurge," the manifesto read. He resisted the urge to eat cat food to supplement his diet, a suggestion he received from an elderly neighbor.

Then, in the late 1980s and early 1990s, Stack said spent $5,000 of his "pocket change" and at least 1,000 hours complaining to elected officials.

"I spent countless hours on the L.A. freeways driving to meetings and any and all of the disorganized professional groups who were attempting to mount a campaign against this atrocity," Stack wrote, without clarifying.

Stack closed the manifesto with mentions of the "communist creed" and the "capitalist creed" and said violence is the "only answer."

"Sadly, though I spent my entire life trying to believe it wasn’t so, but violence not only is the answer, it is the only answer," the note continued. " ... The communist creed: From each according to his ability, to each according to his need. The capitalist creed: From each according to his gullibility, to each according to his greed."

The posting, dated Feb. 18, was signed "Joe Stack (1956-2010)."

Stack's posting was originally found at EmbeddedArt.com, which, before he posted his manifesto, described the firm as a "small independent software house" that specialized in process control and automation. Stack founded the company in 1983 under the name Prowess Engineering in Southern California, where the company was located for 15 years until it shifted to Sacramento.

"Now, 5 years later, the expertise of Embedded Art has landed in the Austin Area expecting to lend a hand to the growing high technology industry in South-Central Texas," the Web site read prior to the posting of the manifesto.

A neighbor of Stack's told KTBC Fox 7 in Austin that Stack was an experienced pilot who did not appear to be in trouble recently.

Stack and his former wife, Ginger, now 57, divorced in May 1999, according to California court records. Attempts to contact his ex-wife were not immediately successful.

Earlier Thursday, Stack's $232,000 home in a middle-class neighborhood was engulfed in flames about five miles from the crash site. Two law enforcement officials told the Associated Press Stack had apparently set fire to his home prior to the crash.

Neighbor Elbert Hutchins, told the Associated Press that a woman and her teenage daughter drove up to the house before firefighters arrived.

"They both were very, very distraught," said Hutchins, a retiree who said he didn't know the family well. "'That's our house!' they cried 'That's our house!"'

Federal Aviation Administration spokesman Lynn Lunsford told the Associated Press the pilot took off from nearby Georgetown but didn't file a flight plan. According to FAA records, a Piper PA-28 Cherokee with the same tail number as the plan that flew into the building is registered to Joseph A. Stack. He was also required to wear corrective lenses and possess glasses for near and intermediate vision.