A man accused of possessing explosives and chemical weapons told a court he owned books with "lurid titles" but had not broken any laws in buying them.
One entitled "How Terrorists Kill" was one of several found in a raid at Russell Wadge's home in Trimsaran, Carmarthenshire, in 2019, Newport Crown Court heard.
The 59-year-old said it "was not illegal" to buy such books.
He denies 28 charges of possessing explosive devices and chemical weapons.
'Times have changed'
Mr Wadge said he had been collecting books for 40 years and was previously visited by the authorities after buying 12 books from America when he was 23.
"I had a visit from Special Branch, it was not illegal to buy the books. He looked at [the collection] and off I went," he said.
Mr Wadge accepted some of the books would not be published today.
"Times have changed. This is not considered politically correct, it wouldn't be considered safe. I don't think anyone will dare to provide this information in the future," he said.
Continuing his defence, Mr Wadge was asked about another book found at his property called "War Gasses".
He said he had been planning to undertake a series of experiments with his son that would be "something edgy".
"As far as I'm aware it is legal to make small quantities of things from that book, eg, mustard gas," he said.
Mr Wadge added that despite having a collection of grenades, it "doesn't make sense" that he would be planning a "terrorist outrage" as the weapons were "pretty".
He told jurors: "I thought it was perfectly permissible to buy anything I wanted as long as I didn't combine them to make explosives.
"Everything is legal until the police turn up and say you're making explosives and you're obliged to prove your innocence. I should be free to buy whatever I damn well want."
On Wednesday, the defendant told the court "people who love explosives are not necessarily bad people".
Last week, prosecutors said Mr Wadge had a significant interest in white supremacy.
The trial continues.