"All the arguments to prove man's superiority cannot shatter this hard fact: in suffering, the animals are our equals."
It is 40 years since Australian philosopher Peter Singer wrote this truth in book that shook our understanding of animals and continues to shape the way we treat them.
His 1975 work, Animal Liberation: A New Ethics for Our Treatment of Animals was a philosophical equivalent of an earthquake that continues to resonate through the decades.
Singer's observations were not new; concern about the reality of animal suffering stretches back through history. Singer's Animal Liberation echoes the great thinker Jeremy Bentham's observations in 1789, that the basis of animal welfare "is not can they reason, nor can they talk, but can they suffer?"
While Singer built on the work of many it can be fairly said that his work from forty years ago is the cornerstone of the modern animal welfare movement. This movement is widely described as the last of the great movements for equality: and equal right to be free from terror, pain and suffering.
The many animal welfare and animal rights groups born out of the Animal Liberation movement have had an enormous impact; society is catching up.
It is no longer publically acceptable to torment, torture or neglect the wellbeing of animals - whether it is perpetrated in an open backyard, on a racetrack or in the full glare of a circus ring. It is not acceptable to be cruel to animals behind closed doors in a factory farm, an abattoir or a laboratory.
It is no longer publicly acceptable to justify the suffering of animals with the excuse of tradition, entertainment or profit.
But this hasn't happened by itself.
The truth of real physical harm and terrible suffering inflicted on thousands upon thousands of animals every day for our convenience, curiosity, profit and pleasure, has only become repugnant to everyday Australians because of the courageous and traumatic work of those who bear witness to that suffering, and who risk their own wellbeing to make sure Australians know the truth when animals suffer.
It is not governments that are effecting the change to stop the needless suffering of animals, despite their unassailable power to stop barbarism and cruelty visited on the animals we control. In fact successive Australian state and federal governments continue to seek to punish and silence those who speak the truth about such cruelty. These politicians work to protect or excuse the perpetrators of the animal cruelty in institutions, industries and businesses.
Last week Tony Abbott's Liberal-National government threw its weight behind Senator Chris Back's bill to prosecute whistle blowers and investigators who expose animal cruelty.
The Law Council of Australia in their submission to the bill said: ‘the Bill does not target those who engage in malicious cruelty directed at animals, nor those who merely witness such conduct, but only those who make recordings of acts of cruelty'.
The Animal Law institute in their submission said: ‘the true intention of the Bill, being to protect the profitability of animal industries, is evidenced by the inclusion of section 385.20, which increases an offence to an aggravated offence where there has been economic damage to an animal enterprise'.
Some of the recent ground breaking investigations that have exposed cruelty to animals could not have occurred if the Back bill was passed. The greyhound industry across Australia would be continuing to use animals as live bait if not for the work of Animals Australia and Animal Liberation Queensland that has shaken up the industry across the country.
The Greens will continue to work with the community, with welfare advocate, cross benchers and Labor to ensure this bill is not passed so that brave animal welfare organisations and individuals who are shining lights on the dark recesses of animal cruelty in Australia can continue to do their job.