Lectures on the Ethics of T. H. Green, Mr. Herbert Spencer, and J. Martineau

Sidgwick's core objection to Green is methodological: even granting Green's metaphysical arguments about the self-distinguishing consciousness and the common good, there remains what Sidgwick calls a great logical gap between that metaphysics and any concrete ethical conclusion. Sidgwick argues that Green's account of the good will and true good obscures the possibility of willing what one judges to be bad—a phenomenon Sidgwick considers obvious and central to moral responsibility. David O. Brink has observed that Sidgwick never engages Green's perfectionism sympathetically, which prevents him from recognizing both its strengths and the potential weaknesses in his own hedonism [citation:13].

Sidgwick's most penetrating criticism is that Spencer's purported deductions from the law of equal freedom are repeatedly adjusted by considerations that belong to empirical utilitarianism. In the lectures on Spencer's justice, Sidgwick claims Spencer frequently adjusts his deductions by empirical utilitarian expediency, and concludes that regarding Spencer's 'Relative Ethics,' Spencer does not really offer any general system other than Empirical Utilitarianism. This is a charge of concealed inconsistency: Spencer presents his ethics as a deductive science grounded in evolution, but its operative content is utilitarian calculation dressed in evolutionary vocabulary [citation:5].

Sidgwick died in 1900, and the volume was assembled from his lecture manuscripts by E. E. Constance Jones, who signed the preface and prepared the text for Macmillan in 1902 [citation:1]. The Cambridge Library Collection reissued it in 2011–2012 with the Jones editorial apparatus intact [citation:6]. Readers should therefore treat the text as a posthumous editorial construction rather than a work Sidgwick himself saw through the press. The order of lectures, the selection of material on Martineau, and any smoothing of unfinished prose are Jones's decisions, not Sidgwick's final intentions.

The Lectures extend the critical method of The Methods of Ethics (1874) into adversarial territory. In Methods, Sidgwick tested common-sense morality and utilitarianism against each other; in the Lectures, he applies the same demand for rigor to three contemporary systematic rivals. The relationship is one of methodological continuity rather than doctrinal revision. Where Green builds ethics on metaphysics, Spencer on biology, and Martineau on intuition, Sidgwick consistently asks whether these foundations actually generate the determinate guidance they promise. The Lectures thus function as a stress test of the very possibility of a 'method' in ethics against systems that claim to have found a shortcut.

J. B. Schneewind's assessment is that Sidgwick's criticisms of Spencer are 'universally devastating,' targeting Spencer's 'muddled eclecticism and dogmatic eccentricity' [citation:5]. Later readers, however, have noted that Sidgwick was not uniformly hostile: he conceded in earlier writing that Spencer's explanation of moral development was 'highly plausible' and endorsed the proposition that 'pleasure is the ultimate good' while rejecting Spencer's meaning of 'good' [citation:5]. The lectures themselves present a more nuanced picture than the caricature of Sidgwick as simply dismissive: he distinguishes between Spencer's empirical utilitarian substance, which he partly accepts, and Spencer's deductive pretensions, which he rejects.

The most persistent misreading treats the volume as a neutral historical survey of three ethical systems. It is not. The lecture format is adversarial throughout: each section is structured around identifying an error or obscurity in the target author's argument. Sidgwick's aim is not to expound Green, Spencer, or Martineau sympathetically but to determine whether their theories survive his standards of philosophical precision. Readers who approach the book expecting a balanced introduction to British idealism or evolutionary ethics will find instead a prosecutor's brief. The correct expectation is that of watching a rigorous utilitarian intuitionist dismantle rival foundations, with all the insight and all the blind spots that such an exercise entails.