to how we would optimally function.

And I'm not talking about a modern technological practice

such as posting embarrassing snapshots of one's unsuspecting partner on Facebook.

I'm talking about an integral human behavior.

I'm talking about a deeply intimate behavior.

Every day we engage in a behavior that requires us

to distort our thoughts, numb our feelings

and act against our core values,

and which enables a global atrocity

that can make even the most stoic of us weep in sorrow.

And every day we could choose not to engage in this behavior,

except we don't realize that it's irrational.

We don't see that it's destructive and we don't even know we have a choice.

How can some of the most frequent and important choices we make,

appear not to be choices at all?

How can the irrationality and destruction of a widespread behavior

be virtually invisible?

These are the questions I asked when I began my nearly two decades of research

on the psychology of eating animals.

And what I discovered was not at all what I had expected.

As it turns out, there's a distinct underlying factor

that both drives our behavior and prevents us

from recognizing its irrationality and the destruction it causes.

I identified and codified this factor

and I'm here to share my findings with you.

And the good news is that simply becoming aware of this factor

enables us to reclaim our rationality and freedom of choice

and become more active participants in creating a humane and just world.

My journey of discovery began in 1968,

25 years before I set foot in my first Harvard lecture.

And nearly fifty years before

I received the Ahimsa Award at the British House of Commons

for my work on global non-violence.

I'm 48. Thank you.

(Laughter)

My family adopted a puppy we named Fritz.

Now, Fritz was my first dog and he was also my first friend.

We did everything together.

We played together. We napped together.

And we even vomited together once during a sickening road trip.

And Fritz was also my first heartbreak

when he died at the age of 13 of liver cancer.

What I didn't realize back then was that my connection with Fritz

would lead to a discovery that would transform my worldview.

So I cared about Fritz and I'm not unique.

Most of us care about animals.

We teach our children to be kind to animals.

Our hearts leap when we witness them at play.

We recognize the injustice and feel outraged when they are abused.

We empathize with animals.

We share their fear, their joy, their sorrow.

And how many of you have cared about a certain animal in your life?

Just raise your hand.

Now look around the room.

That's a whole lot of caring.

So to explain how my connection with my dog

led me to this stage, I'd like to do a thought experiment.

Imagine that you're a guest at a dinner party

and your host serves you a dish that looks like this.

Consider whether you find this delicious or disgusting.

For those who would find it delicious,

imagine you find it so delicious that you ask your host for the recipe.

And she replies the secret is in the meat.

You use three pounds of well-seasoned -

Golden Retriever.

Now take a moment to reflect on your thoughts and feelings.

Chances are, what you had just thought of as food,

you now think of as a dead animal.

What you just felt was delicious, you now feel is disgusting.

Chances are, your experience of the meat dramatically changed.

Even though nothing about the meat itself actually changed.

So what changed?

Well, what changed is your perception of the meat.

When it comes to eating animals our perception is shaped

largely, if not entirely, by our culture.

In meat-eating cultures around the world,

out of over seven million animal species,

people tend to classify only a handful as edible.

All the rest are inedible and disgusting.

So the question is, why are we not disgusted

by the select species we have learned to think of as edible?

And why don't we ever ask why?

Have you ever wondered why you might eat certain animals but not others?

Have you ever wondered why you haven't wondered?

For much of my life I never wondered about my choice to eat certain animals

because I never even knew I had a choice.

No one had ever asked me if I believed in eating animals.

Eating animals was just a given.

So, I never thought about how strange it was

that I could pet my dog with one hand, while I ate a pork chop with the other.

A pork chop that had once been an animal

who was at least as sentient and intelligent as my dog.

And frankly I didn't want to think about this contradiction;

it was just easier not to.

It wasn't until 1989 that I started asking why.

I had been hospitalized after eating what would be my very last hamburger.

A burger that was contaminated with the dangerous bacteria Campylobacter.

After being so sick I swore off meat.

And then something interesting happened.

When I stopped eating animals I had a paradigm shift.

In other words, I didn't see different things,

I saw the same things differently.

Beef stew seemed no different than golden retriever stew.

And everywhere I turned I saw people putting the bodies of dead animals

into their mouth as though nothing at all were wrong.

So I became very curious as to how rational caring people, like myself,

could just stop thinking and feeling.

Well, two advanced degrees later, I had my answer.

And this is what I discovered:

There is an invisible belief system or ideology

that conditions us to eat certain animals.

And I named the system: Carnism.

We tend to assume that only vegans and vegetarians follow a belief system.

But when eating animals is not a necessity

- which is the case in much of the world today -

then it is a choice.

And choices always stem from beliefs.

Now carnism is a dominant ideology.

Meaning that it's so widespread,

its doctrine is seen as a given rather than a choice.

Eating animals is just the way things are.

And it is a violent ideology.

Meat cannot be procured without violence.

And egg and dairy production cause extensive harm to animals.

Ideologies such as carnism run counter to core human values.

Values such as compassion, justice and authenticity.

And so they need to use defense mechanisms

that distort our thoughts and numb our feelings

so that we act against our values without fully realizing what we are doing.

Now, the main defense of carnism is denial,

which is expressed largely through invisibility.

The ideology itself is invisible

and so are its victims.

For instance, 1.2 billion farmed animals are slaughtered globally every week.

So in one week more farmed animals are killed

than the total number of people killed in all wars throughout history.

But how many of these animals have you seen?

Where are they?

Approximately 98 percent of the meat, eggs and dairy we eat

comes from animals who were raised in factory farms.

Windowless sheds in remote locations

that are virtually impossible to obtain access to.

Yet, although these animals are treated as commodities,

they are in fact sentient, intelligent individuals

with lives that matter to them.

In a moment I'm going to show a two-minute video

of animal factories which can be difficult to watch.

So I want to remind you that my intention is simply to raise awareness.

So I have to make the invisible visible.

I've selected material that I think is sufficient to inform you,

without traumatizing you.

But if it's too difficult to watch, just close your eyes and plug your ears.

(Video)

Piglets are castrated by workers who cut into their skin

and rip out their testicles.

(Piglet squeal)

Next the workers chop off their tail.

Once pigs have reached market weight, they are sent to slaughter.

At the slaughterhouse pigs are knocked in the head with a steal rod,

hung upside down and have their throats slit.

(Pig squeal)

Improper stunning condemns many pigs

to having their throats slit while they are fully conscious and suffering.

Because male chicks don't lay eggs,

and do not grow quickly enough to be raised profitably for meat,

they are killed within hours after hatching.

The females have it even worse.

Workers use a hot blade or laser to remove part of the chicks' beaks.

At the slaughter plant, the birds are dumped from their crates,

then roughly snapped upside down

into moving shackles by their fragile legs.

They are then pulled across a blade which slices their throats