Principles of Equity

Henry Home, Lord Kames, was the complete
“Enlightenment man,” concerned with the full
spectrum of human knowledge and its social use. However,
as a lawyer and, after 1752, as a judge on the Court of
Session in Edinburgh, he made many of his most distinctive
contributions through his works on the nature of law and
legal development. Principles of Equity, first
published in 1760, is considered his most lasting
contribution to jurisprudence and is still cited.

In his jurisprudence, Kames specifically sought to
explain the distinction between the nature of equity and
common law and to address related questions, such as
whether equity should be bound by rules and whether
there should be separate courts of law and equity.

Beginning with a general introduction on the rise and
nature of equity, Principles of Equity is divided into
three books. The first two, “theoretical,” books examine
the powers of a court of equity as derived from justice
and from utility, the two great principles Kames felt
governed equity. The third book aims to be more
practical, showing the application of these powers to
several subjects, such as bankrupts.

Principles of Equity is significant as an example
of the approach of an Enlightenment thinker to practical
legal questions and as an early attempt to reduce law to
principles. There is evidence that this book was well
known in the formative years of the United States and that
both Benjamin Franklin and Thomas Jefferson were
familiar with Kames’s treatise.

Henry Home, Lord Kames (1696–1782), one of the leaders of the Scottish Enlightenment, was a judge in the supreme
courts of Scotland and wrote extensively on morals, religion, education, aesthetics, history,
political economy, and law, including natural law. His most distinctive contribution came through
his works on the nature of law, where he sought to combine a philosophical approach with an
empirical history of legal evolution.

Michael Lobban is Professor of Legal History at Queen Mary, University of London.



Knud Haakonssen is Professor of Intellectual History and Director of the Centre for Intellectual History at the University of Sussex, England.