An animal rights campaigner has denied planting home-made petrol bombs at two Oxford University sites.
Mel Broughton, 50, of Semilong Road, Northampton, allegedly targeted Queen's College sports pavilion in 2006 and Templeton College the following year.
He told the jury that he had set up a campaign group to oppose Oxford University's plans for a research laboratory.
Mr Broughton denies a charge of conspiracy to commit arson.
'A lot older'
The jury at Oxford Crown Court was told how Mr Broughton had pleaded guilty to being in possession of firebombs in 1998, and was jailed for four years.
Taking the stand, he said: "I am no longer involved in that type of action.
"I do understand why people break the law to help animals.
"It would be hypocritical to say I don't understand it. I do, but I am no longer involved."
David Bentley, defending Mr Broughton, asked him if he was someone who had a "propensity to use firebombs?"
He said: "No, no I wasn't."
Mr Bentley then asked what had changed.
He replied: "I am a lot older. For me it's no longer something I am willing or able to do"
As well as conspiracy to commit arson, Mr Broughton also denies an alternative charge of possession of an article with intent to destroy property.
The trial continues.