I’d say that developing a “vegan mind”--the gentle, caring, loving attitude towards all creatures, and not least towards other humans--is a spiritual requisite. For a person to contend they speak for voiceless animals, or the oppressed, or against injustice, yet berate people for their beliefs or actions, is, itself, a hypocritical stance. We must somehow love and respect those with whom we disagree, as most spiritual paths teach, not browbeating one’s truth into another. THAT--the loving attitude--is the most difficult place to which I hope we can all aspire to. That is the “vegan mindset.” This remains true even if one contends that the truth she is espousing is a “universal truth” or that one is speaking for the oppressed. In any case, one’s tone is sometimes as important, possibly more so, than the content. People tend to hear HOW something is said--the tone rather than the substance.
Having said that, I recognize that, historically, social justice movements--such as anti-slavery, anti-vivisection, women’s suffrage, civil rights, and so on--have been advanced by those who were proactively on the edge of aggression. However, I believe the jury is still out for those who have been involved in eco-sabotage, as it’s not clear whether their actions have been beneficial. Those in the Animal Rights movement who are involved in civil actions (as I was many years ago) are involved in long-term struggle that has definitely shown some social improvement. Still, one must weigh one’s direct interaction with people and the possible harm that can be engendered, against the effort to make others see the truth. Whether they “see” the truth is probably out of our hands, anyway.
And, harming people, including their feelings, is a real harm. If you contend that not speaking up for the voiceless and the oppressed, or not speaking out about injustice, is a greater harm, then be thankful that you have been blessed with this knowledge. But, also know that the wisdom of carrying your message with love, is a greater calling.
A personal note: I would be loathe to claim I have no hypocrisy in my life. I assume as humans we all have it. Indeed, my response above is rather didactic, on the verge of sanctimoniousness, and was not requested by anyone. I apologize if I cause any hard feelings. Also, in the past I have played the role of the all-knowing orthorexic truth teller; nevertheless, I probably never convinced anyone of anything. (Oops! The above discussion belies that I have left off completely the attempt to spread the "truth!" So, still guilty!) Now, I live by example, whether anyone notices or not. That works!