Mr Kasem said the crisis Thailand has been facing over the past decade is unprecedented.
He described it as a decade of darkness resulting from politics revolving around populist policies which have led people to crave and become addicted to materialism and consumerism.
He said corruption is a serious problem that needs to be addressed urgently.
Mr Kasem said poll figures showing that about 80% of Thais admitted they had been involved in corruption were alarming.
He urged the people, including civil servants, to come out and "light candles" to dispel and counter the darkness of corruption and for the government to make serious efforts to tackle the graft problem.
Members of the media also needed to review their role as they will better serve the public by presenting more issues of substance than by dishing out entertainment stories, Mr Kasem said.
He was speaking at a seminar organised by the Office of the Ombudsman in Bangkok yesterday.
Today, Thai people are adopting some negative social values such as bowing to dishonest people, or admiring and supporting wealthy people who commit wrongdoings, Mr Kasem said.
Ombudsman Sriracha Charoenpanich told the seminar that Thai society has been "seriously ill" and is badly in need of "operations" at almost every level.
Thai people must take a critical look at themselves and restore moral and ethical values while national discipline must also be forged among people to move the country toward progress, Mr Sriracha said.
Obeying the law is also important, he said, adding that advocates of democracy who fail to follow the law end up becoming "impostor defenders of democracy".
Mr Sriracha said Thailand has never had government leaders who truly steered the country towards progress. There have only been those who want to pursue more wealth, he said.
Meanwhile, the Thailand Development Forum also held a separate seminar titled "Assessing the Damage the Political Conflict has on Social Moral Values" in Bangkok yesterday.
Local Development Institute secretary-general Poldej Pinprateep told the seminar that social divisions and distrust among people on both sides of the political chasm have now cut deeply into families.
Mr Poldej said national development has been used as an excuse by politicians to pursue benefits while the people have been exploited as a tool for power struggles.
He believed major changes are on the way soon as the political situation is "very likely to take a turn for the better" early next month.
However, the social discord may not go away, he said.
Sakorn Songma, a representative of a non-government organisation in Phitsanulok, said the current political conflict has accentuated the struggle between those in power and in charge of allocating resources, and the people.
However, even though people have felt they are being taken advantage of by politicians who have captured the lion's share of resource allocation, when elections are called they still vote for those politicians, Mr Sakorn said.