Yet, for all his belief in the goodness of life, Mani's films show that life is too complicated for goodness to permeate it completely.
In Mani Ratnam's latest film O Kadhal Kanmani, a boy and a girl meet for the first time but it looks like they've known each other forever.
(Image, left: Dulquer Salmaan and Nithya Menen in O Kadhal Kanmani)
We accept the characters and situations here, like in every Mani Ratnam creation, wholly and unquestionably because we understand that the director genuinely believes in spontaneous attraction.
It is this innocence that makes Mani Ratnam the master of heartfelt contrivances and absolute manipulations.
So absolute, that when Tara and Adi from O Kadhal Kanmani share their first notes on the man-woman relationship, it seems like they are blissfully unaware of their differences.
It has often been said that Mani Ratnam's characters are inherently good. What is not noticed is how little the major characters change through the course of the movie.
Mani Ratnam's most memorable characters -- be it Divya from Mouna Ragam, Velu from Nayagan, Anandan from Iruvar or the title character of Roja -- never undergo any serious metamorphosis.
At the most, they adapt.
We don't complain about this because, while he sketches these characters with an Amar Chitra Katha-like idealism, he also finds a way to make the idealism seem interesting.
The idealism is sometimes seen as poetic, sometimes as plain generous and sometimes as hip.
This kind of innocence stops him from becoming a sensual director.
Even when dealing with sex, the camera captures only those things that are perpetuated by greeting card companies.
For example, in O Kadhal Kanmani, the camera seemingly looks away when the couple makes love.
In Nayagan, it glides over the lovers.
In Roja, Bombay, Alai Payuthey and Yuva, it is playful sex whose function is to move the plot forward.
In Dil Se..., it is obsession that at times masquerades as attraction.
The one film in which Mani Ratnam was able to capture the sexual tensions between his characters was Iruvar, which is also his greatest film.
The sensuality of Iruvar lies in the fact that it catches its characters in their most insecure and also their most confident moments, both confiding in and hiding from their partners things that make them attractive and banal in equal measure.
There is real sexual tension in that perplexed look on Mohanlal's face when he watches Aishwarya Rai grooving to Hello Mr Ethirkakshi.
Or that wonderful sequence when Prakash Raj professes love to Tabu in a manner not very different from his fiery speeches and yet like a man devoid of his mask.
In Iruvar, the expressions of sexuality weren't just plot-points; they were the deal-makers.
It is the strength of his innocence and the power of his naivete that makes Iruvar Mani Ratnam's most accomplished work.
The outsider in him never zooms in. He chooses to stay an outsider, taking in all the gloss, the raw emotions, at face value and still staying inside his character's head, exploding every now and then with a trick that's more sleight-of-hand than extreme sorcery.
If innocence makes kids endearing, their display of precociousness is what is most off-putting. The same can be said of Mani Ratnam.
A Mani Ratnam film usually disintegrates not when his characters act dewy-eyed, but when he turns the dewy-eyedness of his characters into a device to help us see the world in a different light.
In Roja, when a stoic Arvind Swamy lights his cigarette from a stove and stuffs it in Madhoo's mouth, there is a casual sexiness about it.
However, when the same stoicism leads him to mouth patriotic platitudes, the movie loses its charm and consequently Mani loses his bite.
The idealism of his characters starts to feel like it's being spelt out and the technique seems like it's in the service of the 'message' being relayed.
When Mani colours our fantasies, we give in, but when he tries to control our thoughts, we are compelled to break free.
Audiences are conditioned to believe that anyone who suggests there is a more humane way to exist in this world is acting 'innocently' and hence must be taken seriously.
Rajkumar Hirani's films are often mistakenly considered 'innocent films' and that innocence is often cited as the reason for their charm.
However, what Rajkumar Hirani essentially does is show a set of people who are 'moved' by his innocent characters.
We are very calculatedly made to feel that if we don't become a part of the transformation happening on screen, we may be a tad less human.
Mani Ratnam, on the other hand, has an innocence that's yet to be shaded by this kind of calculation.
For all his belief in the goodness of life, Mani's films show that life is too complicated for goodness to permeate it completely.
When Rajkumar Hirani's protagonists in Munnabhai MBBS put up an act of benevolence at Dhobi Ghat, all the dhobis (washermen) stop to applaud.
The dhobis in a Mani Ratnam film would perhaps watch the act with a feeling of scepticism and continue with their washing.