Communist Manifesto Chap. 3: Socialist and Communist Literature Part 2: Conservative or Bourgeois Socialism
A part of the bourgeoisie is desirous of redressing social grievances in order to secure the continued existence of bourgeois society

To this section belong economists, philanthropists, humanitarians, improvers of the condition of the working class, organisers of charity, members of societies for the prevention of cruelty to animals, temperance fanatics, hole-and-corner reformers of every imaginable kind. This form of socialism has, moreover, been worked out into complete systems

We may cite Proudhon’s Philosophie de la Misère as an example of this form

The Socialistic bourgeois want all the advantages of modern social conditions without the struggles and dangers necessarily resulting therefrom. They desire the existing state of society, minus its revolutionary and disintegrating elements. They wish for a bourgeoisie without a proletariat. The bourgeoisie naturally conceives the world in which it is supreme to be the best; and bourgeois Socialism develops this comfortable conception into various more or less complete systems. In requiring the proletariat to carry out such a system, and thereby to march straightway into the social New Jerusalem, it but requires in reality, that the proletariat should remain within the bounds of existing society, but should cast away all its hateful ideas concerning the bourgeoisie

A second, and more practical, but less systematic, form of this Socialism sought to depreciate every revolutionary movement in the eyes of the working class by showing that no mere political reform, but only a change in the material conditions of existence, in economical relations, could be of any advantage to them. By changes in the material conditions of existence, this form of Socialism, however, by no means understands abolition of the bourgeois relations of production, an abolition that can be affected only by a revolution, but administrative reforms, based on the continued existence of these relations; reforms, therefore, that in no respect affect the relations between capital and labour, but, at the best, lessen the cost, and simplify the administrative work, of bourgeois government

Bourgeois Socialism attains adequate expression when, and only when, it becomes a mere figure of speech

Free trade: for the benefit of the working class. Protective duties: for the benefit of the working class. Prison Reform: for the benefit of the working class. This is the last word and the only seriously meant word of bourgeois socialism

It is summed up in the phrase: the bourgeois is a bourgeois — for the benefit of the working class.