Personal Purity Isn’t Really The Issue. Not

Human Beings Are Social Animals. We Were Social Before We Were Human.

If A Being Suffers There Can Be No Moral Justification For Refusing To Take That Suffering Into Consideration. No Matter What The Nature Of The Being, The Principle Of Equality Requires That Its Suffering Be Counted Equally With The Like Suffering - Insofar As Rough Comparisons Can Be Made - Of Any Other Being. So The Limit Of Sentience Is The Only Defensible Boundary Of Concern For The Interests Of Others. To Mark This Boundary By Some Other Characteristic Like Intelligence Or Rationality Would Be To Mark It In An Arbitrary Manner. Why Not Choose Some Other Characteristic, Like Skin Color?

Human Social Institutions Can Effect The Course Of Human Evolution. Just As Climate, Food Supply, Predators, And Other Natural Forces Of Selection Have Molded Our Nature, So Too Can Our Culture.

If Evolution Is A Struggle For Survival, Why Hasn't It Ruthlessly Eliminated Altruists, Who Seem To Increase Another's Prospects Of Survival At The Cost Of Their Own?

Sci-fi Is Often A Metaphor. I Think It's More The Themes And Questions That Science Fiction Raises Rather Than The Exact Predictions That Should Guide Us.