IF I die... sorry, when I die (how arrogant) feel free to cut me up and use me for parts. Maybe not my stone-riddled, scar-tissued kidneys but the rest of me is fairly sound and you may have what is useful. I like to think of my heart beating in someone else's chest after that heart has ceased to be mine, my lungs swelling with someone else's breath. What else would my dead body be but functionless meat?

This week the British Medical Association has made new calls to bring in a "soft" system of presumed consent in Scotland, meaning people would have to specifically register their desire not to have their organs used after their death. Families would be still be able to withdraw consent but the hope is an "opt-out" system would increase the numbers of patients receiving new organs.

Right now there are 778 people on the transplant waiting list, with organs donated from only 70 people this year. The Herald's sister paper, the Evening Times, is currently running a campaign backing an opt-out system, taking the same stance as the BMA and calling on the Scottish Government to change organ donor policy.

Presumed consent is not an easy change to make, though Wales passed legislation last year to switch to an opt out system by 2015. It is a controversial, even radical, step. Some object, citing distrust in the medical establishment, some make religious arguments, some believe the state has no right to their body, some say forcing a gift of organ donation turns a generous decision into an action by default. Ok, so opt out. An opt-out system would give many the chance to think about why they are saying no and perhaps, on reflection, say yes.

We drink, we smoke, we eat terrible food and avoid exercise. We take our poor old bodies for granted when we're alive and then, when we don't need our bits and pieces any more, we want to keep them for ourselves to rot in the ground or be incinerated. What else can we do with our corpses? Donate them to medical science to be suspended in a specimen jar, pickled for posterity, with gruesome students coming to peer at your blanched, dehydrated tissue? No, ta.

Shakespeare's line "of his bones are coral made..." has always given me a quiet desire to be buried at sea. Up to nine people living restricted, painful lives can be helped by a single donor. With that fact, the other options seem so selfish, particularly as you are more likely to need a transplant than be a registered organ donor.

Evidence from Europe shows that presumed consent raises the number of organs available for transplant. Behavioural economists claim people, faced with difficult choices, will plump for the default position, which is probably why surveys show 90% of people in Scotland support organ donation yet just 37% are registered donors.

Nearly the same number of people opt in to donor schemes in the UK as opt out overseas. Of course, presumed consent alone is not enough. Spain, thought to be the world leader on organ donation, saw improvements only 10 years after introducing presumed consent in 1979: other factors are vital too, such as providing strong support for patients and families and care for those waiting for transplants. Spain has an effective campaign of public education and transplant specialists in all hospitals.

In the end some people are just squeamish about dismantling a body, like a scrapped car. Despite my firm stance, I feel odd about my corneas being taken, though what do I think I'll be looking at in the afterlife? Discomfort and irrational feeling are not good enough excuses when people are dying.

Organ donation is a mark of a caring, generous society. The aim for Scotland, now, should be less have a heart and more, as the BMA suggests, give a heart.