Prime Minister Lee Hsien Loong said that the social harmony we enjoy today is not natural, but an act of will that has been sustained through the decades ("Racial, religious integration an ongoing work: PM"; Oct 5).

Professor Kishore Mahbubani once argued that if our harmony is not the product of a natural development but that of "unforgiving laws", our society will remain forever fragile ("So, what is a Singaporean?"; June 8, 2013).

As social integration is an ongoing work, we should regularly review new issues that emerge, such as fairness in employment, social mobility, income parity and cultural development, as circumstances and expectations change over time.

Potential ill feelings and conflicts between locals and foreign-born residents here should also be included.

If we decide that new regulations are required to deal with any new issues, let us have them.

Laws are only one element in the formulae. Equally crucial is the fair and just execution of laws and regulations.

Mr Lee said that we are "very remarkable" in this respect, pointing out that our police are even-handed in their job.

All our institutions - whether family, racial, religious or governmental - have to play their part.

It is not just these systems that we should be proud of but also our unique way of solving problems, such as how we reach agreement amid debates on sensitive issues.

Singaporeans as well as foreigners here can help raise our harmony and integration to a higher level, by interacting more often and in more diverse ways among us.

This is an area that cannot, and should not, be worked on by laws but has to be improved upon by our individual and collective actions.

Community and government organisations can take the lead and provide more facilities and programmes for interactions across various social groups.

Social, business and other organisations can also make more conscious efforts to recruit members and workers that reflect the diversity of our people.

Ng Ya Ken