To call Lee Kuan Yew my friend would not be quite right. More accurately, we were colleagues. I don't think he had many friends, because he was so focused on doing what was good for the nation, and that would require him sometimes to act against his friends. If he was too friendly with anyone, that could colour his decision, so he was very careful.
Many leaders of countries are honest. India's Jawaharlal Nehru was honest. Julius Nyerere in Tanzania was honest. Manmohan Singh is honest. But that's not enough. You must be prepared to demand honesty and be ruthless with your relatives and friends if they are not. Otherwise you can't get the honest culture established.
Lee Kuan Yew was not only honest, but he was also ruthless in demanding honesty from his colleagues. You could have been his colleague, you could have fought with him through the long march, it didn't matter. If you are dishonest, you're out.
So I think in order to make sure he did not soften in this approach, he was very careful about establishing friendships with people.
I resigned from Cabinet (in 1992) because I had a great difference of view over the use of the Internal Security Act in the 1987 arrests. (In 1987, 22 people - many linked to the Catholic Church - were arrested and detained without trial under the ISA for alleged involvement in a "Marxist conspiracy".)
Lee Kuan Yew thought that mine was a Christian view, because he knew I was a Christian. But it was not a hard-headed political view. We had a difference and the whole Cabinet knew.
The way he saw it depended on his experience, and he had some very traumatic experiences with the communists and how they infiltrated legitimate organisations to get what they wanted. I was looking at it from my point of view, without the experiences he had.
I wouldn't venture to say whether he was right or I was right. So it was not that he was ruthless, but that he saw dangers where I didn't. Whether it was real danger or not remains to be seen.
His greatest strength as a leader was his foresight - his ability to see what is likely to happen, and to persuade people with arguments. Not just words, but the way he put his words across, the way he was able to transmit his conviction to people.
One thing that remains very strongly in my mind is how different he was in his decision-making process from what the general impression was.
The general impression is that he was a leader who, once he had made a decision, he stuck to it. In making decisions, he would canvass ideas and views before he made up his mind. Then when he had come to a conclusion, there would be further discussion and more modifications. He was very keen to listen to people.
Sometimes I managed to change his mind. In his assessment of people, there were instances where he had a very good assessment of someone but I did not. So he argued his case, and I argued my case but he didn't change his mind. Later he discovered that he was not right, so he changed his mind about the person.
I also had differences with him on a couple of policies, but he convinced me to his side.
I had some very strong views about Special Assistance Plan (SAP) schools, which favoured Chinese-language schools, because I thought one or two government schools should be selected for people of other races to enjoy similar special assistance.
He explained that this was because the Chinese schools and the people behind the Chinese schools - the clan associations and their students - were very important components of Singapore.
In fact, in the 1940s and 1950s, the majority of school-going children were in Chinese schools, not in English schools. Yet he had managed to persuade the Chinese community to switch to English as a medium of instruction so that we could have one national-type school with Chinese, Malay or Tamil as the second language.
But in order to get that accepted, he agreed to put a certain number of schools in a special position.
If you look at what's happening in Malaysia today, you will realise how important that decision was.
In the total scheme of things, it was a very small price to pay, and it was key, because first, it changed our whole education system, and second, the timing was fortuitous.
I believe that if he had tried to do it 10 years later, after China had opened up, it would not have been possible. There would have been very strong resistance and I don't think the population would have accepted it.
The other policy I disagreed with him on was the Group Representation Constituency (GRC) system. I was against it because I was probably more of an idealist and not realistic enough.
I felt that if the Chinese in my constituency did not want to elect me, then so be it, because I saw being Singaporean more important than anything else. I thought that if the Chinese Singaporean or the Indian Singaporean was not prepared to vote for someone of another race just because he was of a different race, then there was something basically wrong with our society.
But his argument was that you have to have minority representation in Parliament - so two Chinese with one minority-race candidate in one constituency of three people could be tailored in such a way that you have fair representation of minorities in Parliament.
He felt strongly that if we didn't do this, there would be no minority representation. In making the argument he even offered to put me in a single-seat constituency. So I said: "No, I am not talking about myself!"
But I've come to the position now that it was the right thing to do. But what I disagree with is that GRCs were expanded from three members to five or six.
Though we had disagreements, it was not difficult working with Lee Kuan Yew. He knew that my views were sincere even if he didn't agree with them. He respected people who had different views from him, he didn't think it was because you were not as bright.
He spent many hours sharing his experiences with the younger ministers. When he travelled overseas, he would take quite a few of us along. On these trips, every evening after dinner, we would sit around and talk, and he would give us his assessment after discussions with world leaders.
He never tired of explaining something again and again, until we almost absorbed his culture of thinking and his approach to finding solutions to problems.
Dr Goh Keng Swee once said: The PAP needs Lee more than Lee needs the PAP. And that was the fact. You cannot escape that fact.
I feel that he stepped down as PM in 1990 when he need not have. He was still quite vigorous and healthy and could have led the country for another 10 years.
But he himself was keen that he should go long before he lost his competence.
When he did step down, it was a very poignant moment. I remember it very clearly. It was in the City Hall chambers during the swearing in, and as he was coming down the steps, his eyes were red. It was quite an emotional moment for him, because he had put his whole life into this.