Peter Singer (1946—present), one of world’s most influential living philosophers, is best known for applying rigorous logic to a range of practical issues from animal rights, giving to charity to the ethics of abortion and infanticide.

Singer was born in Melbourne in 1946 to Austrian Jewish Holocaust survivors. As a teen he declared his atheism and refused to celebrate his Bar Mitzvah. After studying law, history and philosophy at Melbourne University, he won a scholarship to Oxford University, writing his thesis on civil disobedience. In 1996 he ran unsuccessfully for the Greens in the Victorian State Parliament, and he has held posts at Melbourne, Monash, New York, London and Princeton Universities. His impact on public debate and academic philosophy cannot be overstated.

A key aspect of Singer’s contributions is the idea of ‘equal consideration of interests’. This informs both his views towards animals and charity. It means that we should consider the interests of any sentient beings who have the capacity to suffer and feel pleasure and pain.

Singer is a consequentialist, which means he defines ethical actions as ones that maximise overall pleasure and reduce overall pain. Part of what makes him such a challenging and influential thinker is his application of utilitarianism to real-world problems to offer counter-intuitive yet compelling solutions.’

Are you speciesist?

While at Oxford, Singer recalls a conversation with a friend over lunch that was the “most formative experience of [his] life”. Singer had the meat spaghetti, whereas his friend opted for the salad. His friend was the “first ethical vegetarian” he’d met. Two weeks later, Singer became a vegetarian and several years later published his seminal work Animal Liberation (1975).

Singer’s argument for not eating meat is more-or-less the same as another utilitarian philosopher, Jeremy Bentham. Bentham wrote that “the question is not can they reason or can they talk, but can they suffer?” Similarly, Singer argues that animals have the capacity to suffer. Just as we rightly condemn torture, we should also condemn practices like factory farming that inflict unjustifiable pain on non-human animals. He coined the term ‘speciesism’ to describe the privileging of humans over other animals.

Giving to charity

In Singer’s essay “Famine, Affluence and Morality” (1972), he argues that people in rich countries have a moral obligation to give to charities that help people in poverty overseas. He uses an analogy of a drowning child: if we were walking past a shallow pond and saw a child drowning, we would wade in and save the child, even if this meant wrecking our favourite and most expensive pair of shoes. Likewise, because we know there are children dying overseas from preventable poverty-related diseases, we should be giving at least some of our income to charities that fight this.

Opponents to Singer argue that his view about giving to charity is psychologically untenable, and that there are differences between giving to charity and saving a drowning child. For example, the physical act of pulling a child out from water is more morally compelling than sending a cheque overseas. Other arguments include: we don’t know the child will definitely be saved when we send the cheque, fighting poverty requires a collective global effort not just an individual donation, and charities are ineffective and have high overhead costs.

Singer concedes that there may be psychological reasons why people would save the drowning child yet don’t give much to charity, but he says even if it seems strange, rationally there are no relevant moral differences between the cases.

Responding to the criticism that charities may not be effective has led Singer to be a proponent of ‘effective altruism’. In his book The Most Good You Can Do (2015) he describes how a number of charity evaluators can recommend the most cost-effective way to do good. Singer recommends giving on a progressive scale, depending on one’s income.

Instead of pursuing careers in academia, some of Singer’s brightest past students have decided to work for Wall Street to make as much money as possible to then give this away to effective charities.

Controversy around infanticide

Singer has faced sustained criticism and protest throughout his career for his views on the sanctity of life and disability – especially in Germany, where in the 90’s, his views were compared to Nazism and university courses that set his books were boycotted. While he has always been a staunch supporter of abortion on the grounds that a foetus lacks self-consciousness and the criteria of personhood, he argues there is no moral difference between abortion in the womb and killing a newborn. Furthermore, because a newborn cannot yet be classified as a person, if its parents do not want it to survive, or if it has an extreme disability meaning that keeping it alive would be very costly, there is potential justification in killing it.

Religious sanctity-of-life critics argue that Singer’s ethics ignore the fundamental sanctity of human life. Disability rights advocates argue that Singer’s views are ableist, explaining that the quality of life of a disabled person is less than that of a non-disabled person ignores the socially-constructed nature of disability – its harms and inconveniences are largely because the built environment is made for able-bodied people.

English Philosopher John Locke (1632—1704) is behind many of the ideas we now take for granted in a liberal democracy. Amongst them, his defence of life and liberty as natural and fundamental human rights.

He was especially known for his liberal, anti-authoritarian theory of the state, his empirical theory of knowledge and his advocacy of religious toleration. Much of Locke’s work is characterised by an opposition to authoritarianism, both at the level of the individual and within institutions such as the government and church.

Born in 1632, in his time he gained fame arguing that the divine right of kings is not supported by scripture. Instead, he defended a limited government whose duty is to protect the rights and liberty of its citizens. This idea is familiar to us now, yet at the time it was revolutionary, arguing against the monarchy as the source of society’s governance. A familiar idea in modern day, at the time it was revolutionary – an argument to depart from the monarchy as the source of society’s governance.

In defending his stance, Locke appealed to the notion of natural rights. He invited us to imagine an initial ‘state of nature’ with no government, police or private property. Locke argued that humans could discover, through careful reasoning, that there are natural laws which suggest that we have natural rights to our own persons and to our own labour.

Eventually we could reason that we should create a social contract with others. Out of this contract would emerge our political obligations and the institution of private property. In Locke’s version of the social contract, a human “divests himself of his natural liberty, and puts on the bonds of civil society…agreeing with other men to join and unite into a community” and by submitting to majority rule form a government designed to protect their rights.

The limits of power

Locke’s argument also places limits on the proper use of power by government authorities. While civil society, as viewed through Locke’s liberalism, sees that the individual must sacrifice – or at least compromise – his/her freedom in the name of the public good, the public good ought not to interfere with the individual’s freedom.

Due to this emphasis on liberty, Locke defended a distinction between a public and a private realm. The public realm is that of politics and the individual’s role in the community as a part of the state, which may include, for example, voting or fighting for one’s country. The private realm is that of domesticity where power is parental (traditionally, ‘paternal’).

For Locke, government should not interfere in the private realm. He held the argument that citizens were entitled to protest or revolt or disband a government when it failed to protect their collective interests. On this view it is crucial we distinguish the legitimate from the illegitimate functions of institutions.

Locke asked us to use reason in order to seek the truth, rather than simply accept the opinion of those in positions of power or be swayed by superstition. In this way, we see Locke as an Enlightenment thinker –our natural reason a light that shines, guiding our understanding in order to reveal knowledge.

Knowledge and personal identity

As an empiricist, Locke believed we gain our knowledge through experiences in the world. In contrast to the views of his rationalist predecessor Descartes, Locke argued that we are born as a blank slate or a tabula rasa. This means that at birth our mind has no innate ideas – it is blank. As our mind develops, sensations give rise to simple ideas, from which we form those more complex.

This theory of learning gives rise to another radical idea for his time. Locke asserted that in order to help children avoid developing bad thinking habits, they should be trained to base their beliefs on sound evidence. The strength of our belief should correlate to how strong or weak the evidence for it happens to be.

Furthermore, for Locke, our consciousness is what makes us ‘us’, constituting our personal identity.

Locke’s legacy

We see Locke’s legacy in the 1776 US Declaration of Independence, which was founded on his natural rights theory of government and proclaimed ‘we hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness’.

Following on from his theory of human rights, we also see Locke’s legacy in the Universal Declaration of Human Rights, which was adopted by the United Nations General Assembly on 10 December 1948. Philosophers debate as to whether such rights are indeed ‘natural’, or whether they have been ‘constructed’ and agreed upon by society as useful rules to adopt and enforce.

Locke’s lasting legacy is the argument that society ought to be ruled democratically in such a way as to protect the liberty and rights of its citizens. And that the government should never over-step its boundaries and must always remember it is a glorified secretary of the people.