Age should not be the only factor taken into consideration when choosing future prime ministers ("Future PMs should take office at a younger age" by Mr Aaron Ang Chin Guan; last Saturday).

There are many other more important and compelling criteria to be considered holistically.

To be an effective prime minister, a certain degree of maturity is inevitable, and that can only come with age.

But age should not end up as a straitjacket when selecting future prime ministers.

Mr Ang cited how Singapore's prime ministers had been taking office at successively older ages.

Founding prime minister Lee Kuan Yew took office at 35, Mr Goh Chok Tong at 49 and Prime Minister Lee Hsien Loong at 52.

But the political climate was very different when Mr Lee Kuan Yew took office in 1959.

Singapore was a newly self-governing state. The late Mr Lee had no time for training in key ministries or as deputy prime minister, as his successors did. He had to quickly take charge.

The late Mr Lee was selected as prime minister for his leadership qualities, rather than his age.

His successors, however, had the luxury of exposure in different key posts, including as deputy prime minister, before becoming prime minister.

Singapore had become prosperous and stable by then to allow such training.

And such exposure and training have to continue for future prime ministers.

The rotation of ministers with prime-minister potential in various ministries cannot be dispensed with.

This also allows the potential candidate to be assessed by his colleagues, who will ultimately be the ones to select the leader among them.

Pavithran Vidyadharan