The election of a lone opposition member to parliament has brought home to Singapore a new sense of how delicate is the carefully shaped framework on which this tiny nation is built.
A rumpled but highly intelligent lawyer named J. B. Jeyaretnam hardly seems a threat to Singapore. His presence in parliament is unlikely to launch a revolution - opposed as he is by 74 members of the ruling People's Action Party (PAP) led by the formidable prime minister, Lee Kuan Yew.
Still Jeyaretnam seems to have spoiled the government's well-laid plans.
There had been no parliamentary opposition for years. The once active and radical opposition never recovered from a massive roundup ordered by Mr. Lee in 1963.
Under Singapore's one-party parliament, the material rewards for political passivity were great: rapid, sustained economic growth and a standard of living second in Asia only to Japan's.
In recent years, as his confidence in Singapore's stability grew, Singapore's Premier Lee started to encourage a very gradual increase in political activism. He encouraged PAP members of parliament to be a little more critical of government policies. He also started to groom a handful of bright young technocrats, usually called the ''second-generation leadership,'' from which Singapore's next leaders would probably be chosen.
Mr. Jeyaretnam has suddenly put these carefully laid plans under a greater test than before. Now Mr. Lee and his veteran lieutenants find they have to take him on personally in parliament. The ''second-generation leadership,'' who did their apprenticeship at a time of one-party dominance, are unaccustomed to parliamentary cut and thrust.
Most important, Jeyaretnam's election seems to have revealed a deep-seated resentment of the PAP that the government had not understood.
The PAP currently tends to explain Mr. Jeyaretnam's success in terms of a generation gap. Members suggest that a new generation of affluent but jaded voters wants, as a senior official put it, ''more and fun games'' in their politics.
The solution they offer is to put another program in the computer: The government will shortly be making moral education compulsory in Singapore schools. Parents will have a choice of six religions or ethical systems for their children. All will be designed to instill in new generations of Singaporeans the moral values the government fears are now being lost.
Some people doubt that morality can be legislated. Others challenge the government's analysis of the Jeyaretnam phenomenon.
Correspondence in the Singapore press shortly after Mr. Jeyaretnam's election made it clear that many people, and not just the younger generation, were deeply irritated by the PAP style of government. Letters accused the PAP of ''arrogance'' and an ''insensitive attitude.'' One person wrote that he had voted opposition for the first time in his life, ''to be heard on issues and mistakes that the PAP lacks the humility to admit and reverse.''
The government considers itself hardheaded: As Mr. Lee puts it, they are willing ''to do the unpleasant things which are necessary and in the long-term interests of the people.''
But despite their tough words, the leaders may have changed their style slightly since Mr. Jeyaretnam's victory.
Observers note that the government has taken great care recently to explain its policies. When the government arrested 10 alleged Muslim extremists recently , several of them reportedly connected to Mr. Jeyaretnam, it surprised everyone by taking them to court, rather than detaining them indefinitely without trial under its internal security act, as it had done in the past.