Even before being veg, I was a Shelleyan, so to speak. When I obtained a copy of
Shelley's Prose or The Trumpet of a Prophecy, Shelley's essays really laid out the case beautifully in both "Essay on the Vegetable System of Diet" and "A Vindication of the Natural Diet".
If the use of animal food be in consequence subversive to the peace of human society (as is argued by Shelley at points), how unwarrantable is the injustice and barbarity which is exercised toward these miserable victims. They are called into existence by human artifice that they may drag out a short and miserable existence of slavery and disease, that their bodies may be mutilated, their social feelings outraged. It were much better a sentient being should never have existed than that it should have existed only to endure unmitigated misery.
In the spiritual component directly from the Bible, at the beginning man and woman were created as vegan.
Like the Peruvian poet Cesar Vallejo wrote in "Our Daily Bread" (as translated by James Wright):
(for Alejandro Gamboa)
Breakfast is drunk down . . . Damp earth
of the cemetery gives off the fragrance of the precious blood.
City of winter . . . the mordant crusade
of a cart that seems to pull behind it
an emotion of fasting that cannot get free!
I wish I could beat on all the doors,
and ask for somebody; and then
look at the poor, and, while they wept softly,
give bits of fresh bread to them.
And plunder the rich of their vineyards
with those two blessed hands
which blasted the nails with one blow of light,
and flew away from the Cross!
Eyelash of morning, you cannot lift yourselves!
Give us our daily bread,
Lord . . . !
Every bone in me belongs to others;
and maybe I robbed them.
I came to take something for myself that maybe
was meant for some other man;
and I start thinking that, if I had not been born,
another poor man could have drunk this coffee.
I feel like a dirty thief . . . Where will I end?
And in this frigid hour, when the earth
has the odor of human dust and is so sad,
I wish I could beat on all the doors
and beg pardon from someone,
and make bits of fresh bread for him
here, in the oven of my heart . . . !