menu

Thinkers

Henry Sidgwick

Modern Ethics · Europe · 1838 to 1900

English moral philosopher who gave utilitarianism its most careful defence. He admitted it was hard to fit self-interest together with the good of all.

What it is

Henry Sidgwick (1838 to 1900) was an English moral philosopher, one of the most influential ethical thinkers of the Victorian era, who taught at Cambridge. His masterpiece, The Methods of Ethics (1874), is often seen as the high point of the classical utilitarian tradition of Bentham and Mill.

He examined the ways people reason about right and wrong, from self-interest to common-sense morality to the greatest happiness of the greatest number, and he tested each one with unusual honesty. He also worked to open higher education to women and helped found Newnham College in Cambridge.

The main ideas

  • The greatest happiness. After testing other approaches, he concluded that universal happiness is the sound basis for a rational ethics.
  • Common sense morality. He argued that the rules of common sense morality rest, in the end, on utilitarian principles.
  • The dualism of practical reason. Rational self-interest and universal benevolence each seem reasonable, and he could not show that they must agree. He called this a dualism of practical reason.
  • Education for women. He was a leading supporter of higher education for women and helped to found Newnham College.

What it looks like in practice

Picture someone asked to give up a comfort in order to help strangers far away, who wonders whether they are being asked to give up their own good for no reason. Sidgwick would not dismiss the worry: he took both the demand of the common good and the person's own interest seriously, and found no argument that fully reconciles them. This is an illustration of the idea, not a quotation.

Books and moments

  • The Methods of Ethics (1874) is his masterpiece and a high point of the utilitarian tradition.
  • His writings on politics and economics include the Principles of Political Economy and the Elements of Politics.
  • The Society for Psychical Research was founded with his help, and he took a close interest in its work.

Questions and criticism

  • Is reason divided against itself? His admission of a dualism has been called an honest end to a long search and a flaw in his utilitarianism.
  • Is he a utilitarian? Some commentators call him a dualist or a dual-source theorist instead.
  • Why psychical research? He hoped to find evidence that moral conduct is rewarded after death, which might close the gap between self-interest and duty.

Close neighbours

He built on Bentham and Mill, and later utilitarians such as Moore, Russell, Parfit and Singer drew on him. The pages on Bentham, Mill and Utilitarianism show the tradition he completed.

Written by epchē in our own words, and checked against independent sources on 9 October 2026. The sources are listed below.

Philosophies they belong to or are close to

Who they connect to

Influenced

  • Derek Parfit · Parfit called Sidgwick the greatest of the modern moral philosophers and built on his arguments.
  • Peter Singer · Singer's defence of impartial concern draws on Sidgwick's point of view of the universe.

Influenced by

  • Immanuel Kant · Sidgwick took Kant's principle of universal reasons seriously and blended it with his own view.
  • John Stuart Mill · Sidgwick set out to give Mill's utilitarianism a firmer basis.

Other Modern Ethics thinkers

Sources we used

See where you stand Find them on the map

Something wrong or missing on this page? Tell us.