I believe it's more of a spectrum.

That said, I think people should drop the notion that humans are rational. We're boundedly rational, and this is balanced with logical reasoning.

It's often said in pop culture/society that being rational is somehow "better" than being emotional. I used to believe this long ago, but now I think that's bull. Emotions exist for a perfectly valid purpose, as a guide to our environment and how to interact with and control it. The fact is many humans make decisions or process information on solely emotive rather than rational pretexts. As an example, two queues were open at the supermarket the other day. The first had a really obese woman serving but was far shorter. The second had a cute Indian woman serving, but was far longer. I took the longer queue, just to say hello/making chit-chat/flirt with the cute woman. To some this is "irrational", but to me it's emotive and instinctual. And generally this is how humans often behave in the real world, and there is nothing wrong in that.

Well, isn't the central end of humanity (nay all sentient life) contentment and ease?

Seems like a strange assumption. Indeed, the reverse is often argued, that the central end of life is to be constantly facing challenges, to never be content, that we should seek out not ease but difficulty.

"How dull it is to pause, to make an end, To rust unburnished, not to shine in use!"

Moreover, even if your assertion were true for humans, and even all mammals, we can imagine non-mammalian sentient life.

Medicine? It's an evil practice, which in contemporary times seeks to push its own ethical agenda onto the masses.

If we go extinct, so be it.

It may not even be our own doing per se. We could evolve into a new species in the homo genus, and either they kill us out, or we get naturally not selected.

Or we meet aliens in the Pleaides 700 years from now, who wage a war against us, win and exterminate us as punishment for engaging in war with them.

Depends.

A basic principle in all investing is higher risk equates with higher return.

Also, one has to be intuitive and see how they feel things pan out. for instance, one could have invested shares in Samsung a few years ago, if they had an insight that the Galaxy phone range/Galaxy Tab would kick off. So it's good to be able to weigh up prospects and see the writing on the wall as it were.

A developing economy is simply that, an economy with a comparatively lower living standard. And yes, developing economies do grow higher than advanced economies. This is empirical economic fact. It has little to do with infrastructure, however as people are poorer there is more scope for growth.

The classic argument may be that retarded/invalid humans cannot reason, however we show humanity towards them.

I would in general though, discrimination is deemed wrong since the sufferer is not just hurt but perceives an injustice against his or her being.

Whether animals hold the capacity for this abstract thought remains to be seen. My own opinion is that human intelligence is not so more advanced than that of another mammals, or reptiles or birds even.

That said, I would never condone the abuse or torture of an animal. I feel even guilty killing insects and spiders.

Well, isn't the central end of humanity (nay all sentient life) contentment and ease?

I say sentient as all mammals share the same basic physiological responses and needs.