In a rambling, often poetic 47-page letter addressed to the Iran's youth, President Mohammad Khatami has insisted the tide of reform cannot be reversed.
Lame duck? Mr Khatami now has few supporters in parliament
The president admitted there was a long way to go, but cited hardliners adopting liberal slogans during recent elections as proof change is underway.
Mr Khatami is serving out the last year of his presidency, following defeat at disputed legislative polls in February.
Analysts say his supporters are unlikely to be satisfied by the letter.
They see his years in office as golden opportunities to push through changes but which have been wasted.
'No going back'
"There have been changes of such an extent in social, cultural and political relations that it is impossible to return to the period of before the reforms," Mr Khatami said in his "letter for the future".
"We do not pretend that our attempt to defend the rights of the people have succeeded in every domain, nor that the people have seen all their aspirations fulfilled," Mr Khatami conceded, according to AFP news agency. The letter was originally published by Iran's state news agency, Irna.
Mr Khatami insisted Islam and freedoms could co-exist, but blamed a combination of stubborn resistance from hardliners and impatience for the slow pace of reform.
Both Islam and freedoms can co-exist, Mr Khatami insisted
Mr Khatami was swept to power in 1997 and 2001 by mainly young voters eager for change but has faced dogged resistance from hardliners.
The conservative-controlled Council of Guardians has blocked much legislation put forward by Mr Khatami.
Iran's Supreme Leader, Grand Ayatollah Ali Khamenei, has powers that dwarf those of Mr Khatami and is claimed by the conservative camp.
However, Mr Khatami cited the use by conservative politicians of traditionally reformist slogans for democracy and development during the recent parliamentary elections as grounds for optimism.
Mr Khatami's reformists suffered a swingeing defeat during those elections, after more than 2,000 mainly reformist candidates were controversially banned from standing.
He is now considered a lame duck president, with a year left in office and only a rump of reformist supporters left in parliament.
The BBC's Middle East affairs analyst Sadeq Saba says the letter is short on concrete details on how Mr Khatami intends to use his final year in office.
It is unlikely that such a general statement will satisfy his disillusioned supporters who have been expecting a more robust attack on the conservative establishment, Sadeq Saba says.