Editor’s note: This is Chapter 5 of Nalin Swaris’ book Buddhism, Human Rights and Social Renewal, which I will publish in full soon. It contains a radical reassessment of the Buddha’s teaching and it’s relevance to contemporary thought.
The Vāseṭṭha Sutta [Majjhima Nikāya 98] is an extraordinary discourse in which the Buddha demonstrates and affirms the biological unity of the human species. One realises with a start that this clear and unambiguous declaration was made in the sixth century BCE. The Vāseṭṭha Sutta makes the Ethics and Politics of Aristotle pale into insignificance. Only after the Second World War was the unity and equality of the human race acknowledged, at least in theory, in the Universal Declaration of Human Rights.
The Buddha gives this discourse in response to a question by two students of Brahmin theology. What does the Teacher Gotama think, they ask, of the doctrine taught by their masters, that the four separate ranks of society are different by birth and that their social positions are an articulation of their separate natures?
In reply, the Buddha invites the two young scholars to descend from the airy heights of theological speculation and take a look at the world around them. That there are an immense variety of life forms in the world is an empirically verifiable fact. There are different forms of plant life that can be classified into separate species by their distinct marks and environments. The same applies to animal life. But when it comes to the human form, he emphasised, there are no marks to indicate that humans are subdivided into separate species:
Not in the hairs nor in the head
Not in the ears nor in the eyes
Not in the mouth nor in the nose,
Not in the lips nor in the brows
Not in the shoulders or the neck
Not in the belly or the back
Not in the buttocks or the breast
Not in the anus or genitals
Not in the hands nor in the feet
Not in the fingers nor the nails
Not in the knees nor in the thighs
Not in the colour nor in voice
Birth (jāti) produces no distinctive marks as with other kinds of birth.
As corporeal beings, there are indeed perceptible differences among humans.
But the differences spoken of among humans are purely conventional.
The word jāti has connotations of “birth, race or species”. The Buddha exposes and debunks the strategy behind racist and sexist theories, ancient and modern. The human body is morphologically the same. Distinctions are created by selecting one or more features of the body — skin colour, nose shape, texture of hair, genitals — to identify them as ‘marks’ signifying intrinsic biological differences between culturally and socially differentiated people. Despite the Buddha’s unambiguous assertion that all human beings belong to the same jāti, in Sri Lanka the Sinhalese language uses this term to describe different ethnic and caste groups. The Buddha’s preferred term for cultural or ethnic communities was jana, or “people”.
The discourse continues as the Buddha explains how racist and sexist theories feed on the average person’s ignorance and deluded perception of social reality. When a group engages in the same occupation from generation to generation, the illusion arises that a person is a farmer, warrior, priest or ruler by birth. It is because a person practices agriculture that we call him a farmer and not a ruler or priest or soldier. Similarly a person who rules is called a ruler and not a farmer or priest or soldier. A person who lives by warfare is called a soldier and not a ruler or farmer or priest. A person who earns a livelihood by performing ritual acts is called a priest, not a ruler or farmer or soldier. Repeated activities produce the concept of “farmer/ruler/priest/warrior”. To claim that an empirically existing peasant, ruler or priest was produced by divine conceptualisation is false. The practical order is antecedent to the conceptual order. Their teachers, the Buddha tells the two Brahmin youths, gave a spurious 
explanation for occupational differentiation. It is action, not birth, which differentiates people into occupational groups. If society permits it, anyone born into one occupational group can learn the skills of another group and practise that profession. Neither birth nor divine ordination makes a priest; anyone can pick up the bag of tricks, perform rituals and call himself one. It is culture that prevents people from changing their occupations, not nature, as claimed by the Brahmins. The Buddha sums up his analysis in a pithy philosophical formulation:
The world is thus become through action (and is) the conditionally co-arisen result of action.
The implication of this analysis is revolutionary. What humans have produced under specific social and historical conditions, humans can also change. What is necessary is insight into the Law of Conditioned Co-genesis, proper investigation of surrounding conditions and right goal-oriented action.