was a physiological treatise, advocating conjugal prudence and parental responsibility; it argued in favour of early marriage, with a view to the purity of social life; but as early marriage between persons of small means generally implies a large family, leading either to pauperism or to lack of necessary food, clothing, education, and fair start in life for the children, Dr. Knowlton advocated the restriction of the number of the family within the means of subsistence, and stated the methods by which this restriction could be carried out.  The book was never challenged till a disreputable Bristol bookseller put some copies on sale to which he added some improper pictures, and he was prosecuted and convicted.  The publisher of the National Reformer and of Mr. Bradlaugh’s and my books and pamphlets had taken over a stock of Knowlton’s pamphlets among other literature he bought, and he was prosecuted and, to our great dismay, pleaded guilty.  We at once removed our publishing from his hands, and after careful deliberation we decided to publish the incriminated pamphlet in order to test the right of discussion on the population question, when, with the advice to limit the family, information was given as to how that advice could be followed.  We took a little shop, printed the pamphlet, and sent notice to the police that we would commence the sale at a certain day and hour, and ourselves sell the pamphlet, so that no one else might be endangered by our action.  We resigned our offices in the National Secular Society that we might not injure the society, but the executive first, and then the Annual Conference, refused to accept the resignations.  Our position as regarded the pamphlet was simple and definite; had it been brought to us for publication, we stated, we should not have published it, for it was not a treatise of high merit; but, prosecuted as immoral because it advised the limitation of the family, it at once embodied the right of publication.  In a preface to the republished edition, we wrote:—­

“We republish this pamphlet, honestly believing that on all questions affecting the happiness of the people, whether they be theological, political, or social, fullest right of free discussion ought to be maintained at all hazards.  We do not personally endorse all that Dr. Knowlton says:  his ‘Philosophical Proem’ seems to us full of philosophical mistakes, and—­as we are neither of us doctors—­we are not prepared to endorse his medical views; but since progress can only be made through discussion, and no discussion is possible where differing opinions are suppressed, we claim the right to publish all opinions, so that the public, enabled to see all sides of a question, may have the materials for forming a sound judgment.”