To be alive is to be breathing.

Everything we do should contribute to happiness.

What you do to benefit the lives of others will ultimately also benefit you.

Be clear in your mind what you want the outcome of your communication to achieve. If your aim is more than just to vent your anger towards a meat eater and you sincerely want that person to be a kinder more compassionate being, then you must start by seeing them as a kind and compassionate person. If you are unable to see them as kind and compassionate, then how dare you demand them to see themselves that way.

Whatever you want to have happen to you make it happen for others now and eventually but inevitably you will reap the seeds you have sown.

If it were possible to live without causing harm to any living being at all, then indeed we might well choose not to eat carrots or other vegetables. But that is not possible - merely by being alive, we necessarily cause harm to many, many beings: we step on them inadvertently, we breathe them in without noticing, we kill them when we brush our teeth or wash our bodies, etc.

What could be more physical than what you eat, where you live, and who you live with? These are all very physical issues.